The Effects of Static and Moving Spectral Ripple Sensitivity on Unaided and Aided Speech Perception in Noise.

Purpose: This study evaluated whether certain spectral ripple conditions were more informative than others in predicting ecologically relevant unaided and aided speech outcomes. Method: A quasi-experimental study design was used to evaluate 67 older adult hearing aid users with bilateral, symmetrical hearing loss. Speech perception in noise was tested under conditions of unaided and aided, auditory-only and auditory-visual, and 2 types of noise. Predictors included age, audiometric thresholds, audibility, hearing aid compression, and modulation depth detection thresholds for moving (4-Hz) or static (0-Hz) 2-cycle/octave spectral ripples applied to carriers of broadband noise or 2000-Hz low- or high-pass filtered noise. Results: A principal component analysis of the modulation detection data found that broadband and low-pass static and moving ripple detection thresholds loaded onto the first factor whereas high-pass static and moving ripple detection thresholds loaded onto a second factor. A linear mixed model revealed that audibility and the first factor (reflecting broadband and low-pass static and moving ripples) were significantly associated with speech perception performance. Similar results were found for unaided and aided speech scores. The interactions between speech conditions were not significant, suggesting that the relationship between ripples and speech perception was consistent regardless of visual cues or noise condition. High-pass ripple sensitivity was not correlated with speech understanding. Conclusions: The results suggest that, for hearing aid users, poor speech understanding in noise and sensitivity to both static and slow-moving ripples may reflect deficits in the same underlying auditory processing mechanism. Significant factor loadings involving ripple stimuli with low-frequency content may suggest an impaired ability to use temporal fine structure information in the stimulus waveform. Support is provided for the use of spectral ripple testing to predict speech perception outcomes in clinical settings.

Using a Digital Language Processor to Quantify the Auditory Environment and the Effect of Hearing Aids for Adults with Hearing Loss.

BACKGROUND: Auditory environments can influence the communication function of individuals with hearing loss and the effects of hearing aids. Therefore, a tool that can objectively characterize a patient's real-world auditory environments is needed. PURPOSE: To use the Language Environment Analysis (LENA) system to quantify the auditory environments of adults with hearing loss, to examine if the use of hearing aids changes a user's auditory environment, and to determine the association between LENA variables and self-report hearing aid outcome measures. RESEARCH DESIGN: This study used a crossover design. STUDY SAMPLE: Participants included 22 adults with mild-to-moderate hearing loss, age 64-82 yr. INTERVENTION: Participants were fitted with bilateral behind-the-ear hearing aids from a major manufacturer. DATA COLLECTION AND ANALYSIS: The LENA system consists of a digital language processor (DLP) that is worn by an individual and records up to 16 hr of the individual's auditory environment. The recording is then automatically categorized according to time spent in different types of auditory environments (e.g., meaningful speech and TV/electronic sound) by the LENA algorithms. The LENA system also characterizes the user's auditory environment by providing the sound levels of different auditory categories. Participants in the present study wore a LENA DLP in an unaided condition and aided condition, which each lasted six to eight days. Participants wore bilateral hearing aids in the aided condition. Percentage of time spent in each auditory environment, as well as median levels of TV/electronic sounds and speech, were compared between subjects' unaided and aided conditions using paired sample t tests. LENA data were also compared to self-report measures of hearing disability and hearing aid benefit using Pearson correlations. RESULTS: Overall, participants spent the greatest percentage of time in silence (∼40%), relative to other auditory environments. Participants spent ∼12% and 26% of their time in meaningful speech and TV/electronic sound environments, respectively. No significant differences were found between mean percentage of time spent in each auditory environment in the unaided and aided conditions. Median TV/electronic sound levels were on average 2.4 dB lower in the aided condition than in the unaided condition; speech levels were not significantly different between the two conditions. TV/electronic sound and speech levels did not significantly correlate with self-report data. CONCLUSIONS: The LENA system can provide rich data to characterize the everyday auditory environments of older adults with hearing loss. Although TV/electronic sound level was significantly lower in the aided than unaided condition, the use of hearing aids seemed not to substantially change users' auditory environments. Because there is no significant association between objective LENA variables and self-report questionnaire outcomes, these two types of measures may assess different aspects of communication function. The feasibility of using LENA in clinical settings is discussed.

Working Memory and Speech Recognition in Noise Under Ecologically Relevant Listening Conditions: Effects of Visual Cues and Noise Type Among Adults With Hearing Loss.

Purpose: This study evaluated the relationship between working memory (WM) and speech recognition in noise with different noise types as well as in the presence of visual cues. Method: Seventy-six adults with bilateral, mild to moderately severe sensorineural hearing loss (mean age: 69 years) participated. Using a cross-sectional design, 2 measures of WM were taken: a reading span measure, and Word Auditory Recognition and Recall Measure (Smith, Pichora-Fuller, & Alexander, 2016). Speech recognition was measured with the Multi-Modal Lexical Sentence Test for Adults (Kirk et al., 2012) in steady-state noise and 4-talker babble, with and without visual cues. Testing was under unaided conditions. Results: A linear mixed model revealed visual cues and pure-tone average as the only significant predictors of Multi-Modal Lexical Sentence Test outcomes. Neither WM measure nor noise type showed a significant effect. Conclusion: The contribution of WM in explaining unaided speech recognition in noise was negligible and not influenced by noise type or visual cues. We anticipate that with audibility partially restored by hearing aids, the effects of WM will increase. For clinical practice to be affected, more significant effect sizes are needed.

Output signal-to-noise ratio and speech perception in noise: effects of algorithm.

OBJECTIVE: The aims of this study were to: 1) quantify the amount of change in signal-to-noise ratio (SNR) as a result of compression and noise reduction (NR) processing in devices from three hearing aid (HA) manufacturers and 2) use the SNR changes to predict changes in speech perception. We hypothesised that the SNR change would differ across processing type and manufacturer, and that improvements in SNR would relate to improvements in performance. DESIGN: SNR at the output of the HAs was quantified using a phase-inversion technique. A linear mixed model was used to determine whether changes in SNR across HA conditions were predictive of changes in aided speech perception in noise. STUDY SAMPLE: Two groups participated: 25 participants had normal-hearing and 25 participants had mild to moderately severe sensorineural hearing loss. RESULTS: The HAs programmed for both groups changed the SNR by a small, but statistically significant amount. Significant interactions in SNR changes were observed between HA devices and processing types. However, the change in SNR was not predictive of changes in speech perception. CONCLUSION: Although observed significant changes in SNR resulting from compression and NR did not convert to changes in speech perception, these algorithms may serve other purposes.

Binaural Interference and the Effects of Age and Hearing Loss.

BACKGROUND: The existence of binaural interference, defined here as poorer speech recognition with both ears than with the better ear alone, is well documented. Studies have suggested that its prevalence may be higher in the elderly population. However, no study to date has explored binaural interference in groups of younger and older adults in conditions that favor binaural processing (i.e., in spatially separated noise). Also, the effects of hearing loss have not been studied. PURPOSE: To examine binaural interference through speech perception tests, in groups of younger adults with normal hearing, older adults with normal hearing for their age, and older adults with hearing loss. RESEARCH DESIGN: A cross-sectional study. STUDY SAMPLE: Thirty-three participants with symmetric thresholds were recruited from the University of Iowa community. Participants were grouped as follows: younger with normal hearing (18-28 yr, n = 12), older with normal hearing for their age (73-87 yr, n = 9), and older with hearing loss (78-94 yr, n = 12). Prior noise exposure was ruled out. DATA COLLECTION AND ANALYSIS: The Connected Speech Test (CST) and Hearing in Noise Test (HINT) were administered to all participants bilaterally, and to each ear separately. Test materials were presented in the sound field with speech at 0° azimuth and the noise at 180°. The Dichotic Digits Test (DDT) was administered to all participants through earphones. Hearing aids were not used during testing. Group results were compared with repeated measures and one-way analysis of variances, as appropriate. Within-subject analyses using pre-established critical differences for each test were also performed. RESULTS: The HINT revealed no effect of condition (individual ear versus bilateral presentation) using group analysis, although within-subject analysis showed that 27% of the participants had binaural interference (18% had binaural advantage). On the CST, there was significant binaural advantage across all groups with group data analysis, as well as for 12% of the participants at each of the two signal-to-babble ratios (SBRs) tested. One participant had binaural interference at each SBR. Finally, on the DDT, a significant right-ear advantage was found with group data, and for at least some participants. Regarding age effects, more participants in the pooled elderly groups had binaural interference (33.3%) than in the younger group (16.7%), on the HINT. The presence of hearing loss yielded overall lower scores, but none of the comparisons between bilateral and unilateral performance were affected by hearing loss. CONCLUSIONS: Results of within-subject analyses on the HINT agree with previous findings of binaural interference in ≥17% of listeners. Across all groups, a significant right-ear advantage was also seen on the DDT. HINT results support the notion that the prevalence of binaural interference is likely higher in the elderly population. Hearing loss, however, did not affect the differences between bilateral and better unilateral scores. The possibility of binaural interference should be considered when fitting hearing aids to listeners with symmetric hearing loss. Comparing bilateral to unilateral (unaided) performance on tests such as the HINT may provide the clinician with objective data to support subjective preference for one hearing aid as opposed to two.

Construct Validity of the Ecological Momentary Assessment in Audiology Research.

BACKGROUND: Ecological momentary assessment (EMA) is a methodology involving repeated assessments/surveys to collect data describing respondents' current or very recent experiences and related contexts in their natural environments. The use of EMA in audiology research is growing. PURPOSE: This study examined the construct validity (i.e., the degree to which a measurement reflects what it is intended to measure) of EMA in terms of measuring speech understanding and related listening context. Experiment 1 investigated the extent to which individuals can accurately report their speech recognition performance and characterize the listening context in controlled environments. Experiment 2 investigated whether the data aggregated across multiple EMA surveys conducted in uncontrolled, real-world environments would reveal a valid pattern that was consistent with the established relationships between speech understanding, hearing aid use, listening context, and lifestyle. RESEARCH DESIGN: This is an observational study. STUDY SAMPLE: Twelve and twenty-seven adults with hearing impairment participated in Experiments 1 and 2, respectively. DATA COLLECTION AND ANALYSIS: In the laboratory testing of Experiment 1, participants estimated their speech recognition performance in settings wherein the signal-to-noise ratio was fixed or constantly varied across sentences. In the field testing the participants reported the listening context (e.g., noisiness level) of several semicontrolled real-world conversations. Their reports were compared to (1) the context described by normal-hearing observers and (2) the background noise level measured using a sound level meter. In Experiment 2, participants repeatedly reported the degree of speech understanding, hearing aid use, and listening context using paper-and-pencil journals in their natural environments for 1 week. They also carried noise dosimeters to measure the sound level. The associations between (1) speech understanding, hearing aid use, and listening context, (2) dosimeter sound level and self-reported noisiness level, and (3) dosimeter data and lifestyle quantified using the journals were examined. RESULTS: For Experiment 1, the reported and measured speech recognition scores were highly correlated across all test conditions (r = 0.94 to 0.97). The field testing results revealed that most listening context properties reported by the participants were highly consistent with those described by the observers (74-95% consistency), except for noisiness rating (58%). Nevertheless, higher noisiness rating was associated with higher background noise level. For Experiment 2, the EMA results revealed several associations: better speech understanding was associated with the use of hearing aids, front-located speech, and lower dosimeter sound level; higher noisiness rating was associated with higher dosimeter sound level; listeners with more diverse lifestyles tended to have higher dosimeter sound levels. CONCLUSIONS: Adults with hearing impairment were able to report their listening experiences, such as speech understanding, and characterize listening context in controlled environments with reasonable accuracy. The pattern of the data aggregated across multiple EMA surveys conducted in a wide range of uncontrolled real-world environment was consistent with the established knowledge in audiology. The two experiments suggested that, regarding speech understanding and related listening contexts, EMA reflects what it is intended to measure, supporting its construct validity in audiology research.

International Collegium of Rehabilitative Audiology (ICRA) recommendations for the construction of multilingual speech tests. ICRA Working Group on Multilingual Speech Tests.

OBJECTIVE: To provide guidelines for the development of two types of closed-set speech-perception tests that can be applied and interpreted in the same way across languages. The guidelines cover the digit triplet and the matrix sentence tests that are most commonly used to test speech recognition in noise. They were developed by a working group on Multilingual Speech Tests of the International Collegium of Rehabilitative Audiology (ICRA). DESIGN: The recommendations are based on reviews of existing evaluations of the digit triplet and matrix tests as well as on the research experience of members of the ICRA Working Group. They represent the results of a consensus process. RESULTS: The resulting recommendations deal with: Test design and word selection; Talker characteristics; Audio recording and stimulus preparation; Masking noise; Test administration; and Test validation. CONCLUSIONS: By following these guidelines for the development of any new test of this kind, clinicians and researchers working in any language will be able to perform tests whose results can be compared and combined in cross-language studies.

Impact of frequency compression on music perception.

OBJECTIVE: To determine the effects of frequency compression on music perception, and the impact of previous music training and hearing status. It was hypothesized that lesser amounts of compression would be preferred, and that this pattern of preference would be more evident in the musically trained groups. DESIGN: A paired-comparison paradigm was used. Subjects listened to pairs of musical passages as processed by a hearing aid with different frequency-compression settings. Subjects indicated their preferred passage and the strength of their preference. STUDY SAMPLE: Fifty-seven subjects divided in four groups, according to hearing status (normal hearing, mild-to-moderate hearing loss), and previous music experience (trained, not trained). RESULTS: Subjects generally preferred the conditions with the lesser amount of compression. Listeners in the group with previous music training showed stronger preference for less compression than those without training, as did listeners with normal hearing when compared to subjects with hearing loss. CONCLUSIONS: Although less frequency compression was in general preferred, there was more variability in the comparisons involving the default settings for a 50-dB hearing loss (i.e. start frequency 4000 Hz, compression ratio 2.5:1) and no compression, suggesting that mild amounts of compression may not be detrimental to perceived sound quality.

The effect on localization of frequency-specific gain reduction schemes when matched and mismatched across ears.

OBJECTIVE: To evaluate the impact of non-adaptive matched and mismatched gain reduction schemes on localization in spatially-separated noise. DESIGN: Inspired by the function of commercial noise reduction algorithms, five frequency-specific gain reduction filter schemes were created, three for a modulated babble-noise and two for an unmodulated speech-shaped noise. Applying these schemes as both matched and mismatched conditions across ears, localization of five everyday sounds in noise was measured in a virtual environment using insert earphones. The performance in the reference scheme (no gain reduction in either ear) was measured as well. STUDY SAMPLE: Twenty-four adult bilateral hearing-aid users were enrolled in this study. RESULTS: One of the two mismatched gain reduction schemes for the unmodulated noise had a small but negative impact on localization compared to the reference scheme. For that scheme more high-frequency reduction was noted than for the other schemes. Matching gain reduction across ears restored the deteriorated localization performance. No localization performance differences were observed in the modulated babble-noise regardless of whether the scheme was matched or mismatched across ears. CONCLUSIONS: The impact of noise-induced gain reduction on localization in noise was trivial in the study regardless of whether gain reduction schemes were matched or not across ears.

The effect of low-level laser therapy on hearing.

One purported use of low-level laser therapy (LLLT) is to promote healing in damaged cells. The effects of LLLT on hearing loss and tinnitus have received some study, but results have been equivocal. The purpose of this study was to determine if LLLT improved hearing, speech understanding, and/or cochlear function in adults with hearing loss. Using a randomized, double-blind, placebo-controlled design, subjects were assigned to a treatment, placebo, or control group. The treatment group was given LLLT, which consisted of shining low-level lasers onto the outer ear, head, and neck. Each laser treatment lasted approximately five minutes. Three treatments were applied within the course of one week. A battery of auditory tests was administered immediately before the first treatment and immediately after the third treatment. The battery consisted of pure-tone audiometry, the Connected Speech Test, and transient-evoked otoacoustic emissions. Data were analyzed by comparing pre- and posttest results. No statistically significant differences were found between groups for any of the auditory tests. Additionally, no clinically significant differences were found in any individual subjects. This trial is registered with ClinicalTrials.gov (NCT01820416).

The effect of hearing aid technologies on listening in an automobile.

BACKGROUND: Communication while traveling in an automobile often is very difficult for hearing aid users. This is because the automobile/road noise level is usually high, and listeners/drivers often do not have access to visual cues. Since the talker of interest usually is not located in front of the listener/driver, conventional directional processing that places the directivity beam toward the listener's front may not be helpful and, in fact, could have a negative impact on speech recognition (when compared to omnidirectional processing). Recently, technologies have become available in commercial hearing aids that are designed to improve speech recognition and/or listening effort in noisy conditions where talkers are located behind or beside the listener. These technologies include (1) a directional microphone system that uses a backward-facing directivity pattern (Back-DIR processing), (2) a technology that transmits audio signals from the ear with the better signal-to-noise ratio (SNR) to the ear with the poorer SNR (Side-Transmission processing), and (3) a signal processing scheme that suppresses the noise at the ear with the poorer SNR (Side-Suppression processing). PURPOSE: The purpose of the current study was to determine the effect of (1) conventional directional microphones and (2) newer signal processing schemes (Back-DIR, Side-Transmission, and Side-Suppression) on listener's speech recognition performance and preference for communication in a traveling automobile. RESEARCH DESIGN: A single-blinded, repeated-measures design was used. STUDY SAMPLE: Twenty-five adults with bilateral symmetrical sensorineural hearing loss aged 44 through 84 yr participated in the study. DATA COLLECTION AND ANALYSIS: The automobile/road noise and sentences of the Connected Speech Test (CST) were recorded through hearing aids in a standard van moving at a speed of 70 mph on a paved highway. The hearing aids were programmed to omnidirectional microphone, conventional adaptive directional microphone, and the three newer schemes. CST sentences were presented from the side and back of the hearing aids, which were placed on the ears of a manikin. The recorded stimuli were presented to listeners via earphones in a sound-treated booth to assess speech recognition performance and preference with each programmed condition. RESULTS: Compared to omnidirectional microphones, conventional adaptive directional processing had a detrimental effect on speech recognition when speech was presented from the back or side of the listener. Back-DIR and Side-Transmission processing improved speech recognition performance (relative to both omnidirectional and adaptive directional processing) when speech was from the back and side, respectively. The performance with Side-Suppression processing was better than with adaptive directional processing when speech was from the side. The participants' preferences for a given processing scheme were generally consistent with speech recognition results. CONCLUSIONS: The finding that performance with adaptive directional processing was poorer than with omnidirectional microphones demonstrates the importance of selecting the correct microphone technology for different listening situations. The results also suggest the feasibility of using hearing aid technologies to provide a better listening experience for hearing aid users in automobiles.

Hearing-aid users' voices: a factor that could affect directional benefit.

OBJECTIVE: Backward-facing directional processing (Back-DIR) is an algorithm that employs an anti-cardioid directivity pattern to enhance speech arriving from behind the listener. An experiment that was originally designed to evaluate Back-DIR, together with its follow-up experiment, are reported to illustrate how hearing-aid users' voices could affect directional benefit. DESIGN: Speech recognition performance was measured in a speech-180°/noise-0° configuration, with aids programmed to Back-DIR enabled or omnidirectional processing. In the original experiment, the conventional hearing-in-noise test (HINT) was used, wherein listeners repeated heard sentences. In the follow-up experiment, a modified HINT was used, wherein a carrier phrase was presented before each sentence. STUDY SAMPLE: Fifteen adults with sensorineural hearing loss participated in both experiments. RESULTS: Significant Back-DIR benefit (relative to omnidirectional processing) was observed in the follow-up experiment, while not in the original experiment. CONCLUSIONS: In the original experiment, hearing aids were affected by listeners' voices such that Back-DIR was not always activated when the target speech was presented. In the follow-up experiment, listeners' voice effects were eliminated by the carrier phrase activating Back-DIR before the sentences were presented. The results suggest that the effect of hearing-aid technologies is highly dependent on the characteristics of listening conditions.

Characteristics of hearing aid fittings in infants and young children.

OBJECTIVES: Hearing aids (HAs) provide the basis for improving audibility and minimizing developmental delays in children with mild to severe hearing loss. Multiple guidelines exist to recommend methods for optimizing amplification in children, but few previous studies have reported HA fitting outcomes for a large group of children. The present study sought to evaluate the proximity of the fitting to prescriptive targets and aided audibility of speech, as well as survey data from pediatric audiologists who provided HAs for the children in the present study. Deviations from prescriptive target were predicted to have a negative impact on aided audibility. In addition, children who were fitted using verification with probe microphone measurements were expected to have smaller deviations from prescriptive targets and greater audibility than cohorts fitted without these measures. DESIGN: HA fitting data from 195 children with mild to severe hearing losses were analyzed as part of a multicenter study evaluating outcomes in children with hearing loss. Proximity of fitting to prescriptive targets was quantified by calculating the average root-mean-square (RMS) error of the fitting compared with Desired Sensation Level prescriptive targets for 500, 1000, 2000, and 4000 Hz. Aided audibility was quantified using the Speech Intelligibility Index. Survey data from the pediatric audiologists who fit amplification for children in the present study were collected to evaluate trends in fitting practices and relate those patterns to proximity of the fitting to prescriptive targets and aided audibility. RESULTS: More than half (55%) of the children in the study had at least 1 ear that deviated from prescriptive targets by more than 5 dB RMS on average. Deviation from prescriptive target was not predicted by pure-tone average, assessment method, or reliability of assessment. Study location was a significant predictor of proximity to prescriptive target with locations that recruited participants who were fit at multiple clinical locations (University of Iowa and Boys Town National Research Hospital) having larger deviations from target than the location where the participants were recruited primarily from a single, large pediatric audiology clinic (University of North Carolina). Fittings based on average real-ear to coupler differences resulted in larger deviations from prescriptive targets than fittings based on individually measured real-ear to coupler differences. Approximately 26% of the children in the study has aided audibility less than 0.65 on the Speech Intelligibility Index (SII). Aided audibility was significantly predicted by the proximity to prescriptive targets and pure-tone average, but not age in months. CONCLUSIONS: Children in the study had a wide range of fitting outcomes in terms of proximity to prescriptive targets (RMS error) and aided speech audibility (SII). Even when recommended HA verification strategies were reported, fittings often exceeded the criteria for both proximity to the prescriptive target and aided audibility. The implications for optimizing amplification for children are also discussed.

Wordlikeness and word learning in children with hearing loss.

BACKGROUND: The more a novel word conforms to the phonotactics of the language, the more wordlike it is and the easier it is to learn. It is unknown to what extent children with hearing loss (CHL) take advantage of phonotactic cues to support word learning. AIMS: This study investigated whether CHL had similar sensitivities to wordlikeness during a word-learning task as children with normal hearing (CNH). METHODS & PROCEDURES: Sixteen CHL and 24 CNH participated in a novel word-learning task. Novel words varied by English wordlikeness. Recall was tested using a forced-choice identification task wherein foils for each trial related semantically, lexically or not at all. Receptive vocabulary and working memory were also assessed. OUTCOMES & RESULTS: All children were able to identify high wordlike novel words more accurately than low wordlike novel words. The number of errors on identification of words that were moderate in wordlikeness was inversely correlated to vocabulary size (not working memory) and CHL had smaller vocabularies than CNH. When in error, CHL were more likely than CNH to select a semantically related foil. CONCLUSIONS & IMPLICATIONS: Although they are sensitive to extremes in wordlikeness, compared with their peers with normal hearing, CHL present with subtle differences in word learning. Clinical implications for exploiting wordlikeness in service of word learning assessment and intervention are presented.

The contribution of a frequency-compression hearing aid to contralateral cochlear implant performance.

BACKGROUND: Frequency-lowering signal processing in hearing aids has re-emerged as an option to improve audibility of the high frequencies by expanding the input bandwidth. Few studies have investigated the usefulness of the scheme as an option for bimodal users (i.e., combined use of a cochlear implant and a contralateral hearing aid). In this study, that question was posed. PURPOSE: The purposes of this study were (1) to determine if frequency compression was a better bimodal option than conventional amplification and (2) to determine the impact of a frequency-compression hearing aid on speech recognition abilities. RESEARCH DESIGN: There were two separate experiments in this study. The first experiment investigated the contribution of a frequency-compression hearing aid to contralateral cochlear implant (CI) performance for localization and speech perception in noise. The second experiment assessed monaural consonant and vowel perception in quiet using the frequency-compression and conventional hearing aid without the use of a contralateral CI or hearing aid. STUDY SAMPLE: Ten subjects fitted with a cochlear implant and hearing aid participated in the first experiment. Seventeen adult subjects with a cochlear implant and hearing aid or two hearing aids participated in the second experiment. To be included, subjects had to have a history of postlingual deafness, a moderate or moderate-to-severe hearing loss, and have not worn this type of frequency-lowering hearing aid previously. DATA COLLECTION AND ANALYSIS: In the first experiment, performance using the frequency-compression and conventional hearing aids was assessed on tests of sound localization, speech perception in a background of noise, and two self-report questionnaires. In the second experiment, consonant and vowel perception in quiet was assessed monaurally for the two conditions. In both experiments, subjects alternated daily between a frequency-compression and conventional hearing aid for 2 mo. The parameters of frequency compression were set individually for each subject, and audibility was measured for the frequency compression and conventional hearing aid programs by comparing estimations of the Speech Intelligibility Index (SII) using a modified algorithm (Bentler et al, 2011). In both experiments, the outcome measures were administered following the hearing aid fitting to assess performance at baseline and after 2 mo of use. RESULTS: For this group of subjects, the results revealed no significant difference between the frequency-compression and conventional hearing aid on tests of localization and consonant recognition. Spondee-in-noise and vowel perception scores were significantly higher with the conventional hearing aid compared to the frequency-compression hearing aid after 2 mo of use. CONCLUSIONS: These results suggest that, for the subjects in this study, frequency compression is not a better bimodal option than conventional amplification. In addition, speech perception may be negatively influenced by frequency compression because formant frequencies are too severely compressed and can no longer be distinguished.

The equivalence of acceptable noise level (ANL) with English, Mandarin, and non-semantic speech: a study across the U.S. and Taiwan.

OBJECTIVE: Acceptable noise level (ANL) determines the maximum noise level that a listener is willing to accept while listening to speech. The objective of this study was to determine the equivalence of ANL measured using different speech stimuli for native speakers who lived in the U.S. and Taiwan. DESIGN: ANLs were measured using English, Mandarin, and the international speech test signal (ISTS) at each site. The same babble noise was used across speech stimuli. The ANLs were considered equivalent if the difference was unlikely to be greater than 3 dB. STUDY SAMPLE: Thirty adults with normal hearing were recruited at each site. RESULTS: For each site, the equivalence test suggested that the native-language and foreign-language ANLs were equivalent. Between the two sites, ANLs measured using the listener's native language were also equivalent. Although the ISTS ANL obtained within each site was equivalent to, and highly correlated to, the native-language ANL, the data were unable to confirm the equivalence of the ISTS ANLs obtained from the two sites. CONCLUSIONS: The results suggested the possibility of directly comparing ANL measures carried out in different countries using different languages. However, it remains unclear if the ISTS can serve as an international ANL stimulus.

Do older adults have social lifestyles that place fewer demands on hearing?

BACKGROUND: Listening demand, or auditory lifestyle, is an important factor that needs to be considered when selecting a hearing aid and specific amplification features. Although elderly adults often report having fewer listening demands, auditory lifestyles of people in different age groups have not been objectively quantified and compared. Although it is assumed that the social lifestyles of older adults, e.g., retirement, place fewer demands on hearing, this assumption has not been examined empirically. PURPOSE: The purposes of the current study were to (1) objectively characterize and compare the auditory lifestyle of younger and older adults with hearing impairment and (2) examine the relationships between age, social lifestyle, and auditory lifestyle. RESEARCH DESIGN: This is a nonexperimental study using a correlational design. STUDY SAMPLE: Twenty-seven adults with bilateral hearing impairment aged 40-88 yr were recruited and served as subjects. DATA COLLECTION AND ANALYSIS: To objectively quantify auditory lifestyle, participants carried noise dosimeters to measure sound levels in their daily lives for 1 wk. To help interpret the dosimeter data, participants used paper-and-pencil journals to describe their listening activities and environments. The auditory lifestyle was also subjectively quantified by the Auditory Lifestyle and Demand Questionnaire (ALDQ). Three self-report inventories were used to characterize participants' social lifestyles: Social Network Index, Welin Activity Scale, and Social Convoy Questionnaire. RESULTS: A total of 1,267 journal entries covering 2,032 hr of dosimeter recordings were obtained from participants for analyses. Although younger and older participants reported spending comparable time in a given category of listening event, the dosimeter-measured sound level was higher for younger listeners. For auditory lifestyle quantified by dosimeter, correlation analyses revealed that older age was associated with lower Social Network Index scores (smaller social networks) and fewer listening demands. Regression models further indicated that the Social Network Index score more accurately predicted listening demand than age. Finally, path analysis suggested that the effect of age on listening demand was mediated by the Social Network Index score. Self-report auditory lifestyle measured by the ALDQ was not associated with age and social lifestyle. CONCLUSIONS: The results indicate that older listeners tend to encounter quieter listening situations than younger listeners. The data are also consistent with the hypothesis that older adults have less active social lifestyles that place fewer demands on hearing. Therefore, the current study suggests the important role of social lifestyle in listening demand and the need to consider this factor in clinical management of hearing loss.

Evaluation of a transient noise reduction strategy for hearing AIDS.

BACKGROUND: Transient noise can be disruptive for people wearing hearing aids. Ideally, the transient noise should be detected and controlled by the signal processor without disrupting speech and other intended input signals. A technology for detecting and controlling transient noises in hearing aids was evaluated in this study. PURPOSE: The purpose of this study was to evaluate the effectiveness of a transient noise reduction strategy on various transient noises and to determine whether the strategy has a negative impact on sound quality of intended speech inputs. RESEARCH DESIGN: This was a quasi-experimental study. The study involved 24 hearing aid users. Each participant was asked to rate the parameters of speech clarity, transient noise loudness, and overall impression for speech stimuli under the algorithm-on and algorithm-off conditions. During the evaluation, three types of stimuli were used: transient noises, speech, and background noises. The transient noises included "knife on a ceramic board," "mug on a tabletop," "office door slamming," "car door slamming," and "pen tapping on countertop." The speech sentences used for the test were presented by a male speaker in Mandarin. The background noises included "party noise" and "traffic noise." All of these sounds were combined into five listening situations: (1) speech only, (2) transient noise only, (3) speech and transient noise, (4) background noise and transient noise, and (5) speech and background noise and transient noise. RESULTS: There was no significant difference on the ratings of speech clarity between the algorithm-on and algorithm-off (t-test, p = 0.103). Further analysis revealed that speech clarity was significant better at 70 dB SLP than 55 dB SPL (p < 0.001). For transient noise loudness: under the algorithm-off condition, the percentages of subjects rating the transient noise to be somewhat soft, appropriate, somewhat loud, and too loud were 0.2, 47.1, 29.6, and 23.1%, respectively. The corresponding percentages under the algorithm-on were 3.0, 72.6, 22.9, and 1.4%, respectively. A significant difference on the ratings of the transient noise loudness was found between the algorithm-on and algorithm-off (t-test, p < 0.001). For overall impression for speech stimuli: under the algorithm-off condition, the percentage of subjects rating the algorithm to be not helpful at all, somewhat helpful, helpful, and very helpful for speech stimuli were 36.5, 20.8, 33.9, and 8.9%, respectively. Under the algorithm-on condition, the corresponding percentages were 35.0, 19.3, 30.7, and 15.0%, respectively. Statistical analysis revealed there was a significant difference on the ratings of overall impression on speech stimuli. The ratings under the algorithm-on condition were significantly more helpful for speech understanding than the ratings under algorithm-off (t-test, p < 0.001). CONCLUSIONS: The transient noise reduction strategy appropriately controlled the loudness for most of the transient noises and did not affect the sound quality, which could be beneficial to hearing aid wearers.

The influence of audiovisual ceiling performance on the relationship between reverberation and directional benefit: perception and prediction.

OBJECTIVES: Acoustically, directional microphone hearing aids are less able to improve signal-to-noise ratio in more-reverberant environments. However, because auditory-visual (AV) omnidirectional performance is more likely to approach the ceiling level in less-reverberant environments, listeners may perceive a smaller directional benefit in these environments. The first objective of this study was to investigate the influence of AV ceiling performance on the relationship between reverberation and directional benefit. The second objective was to determine whether a modified speech intelligibility index (mSII) model could predict directional benefit across AV listening conditions with different levels of reverberation. DESIGN: Nineteen adults with sensorineural hearing loss were recruited. Directional benefit was measured using the auditory-only (AO) Hearing in Noise Test (HINT) and the AV version of the Connected Speech Test (CST) in environments containing either low or moderate levels of reverberation (reverberation time = 0.2 sec and 0.7 sec, respectively). The AO mSII was calculated for both speech materials. To predict AV directional benefit, the AO mSII was converted to the AV mSII using the correction equations specified by American National Standards Institute S3.5-1997 (R2007) and the new equations developed based on the data collected in a low-reverberation sound booth in a previous study. RESULTS: As the test environment became more reverberant, a decrease in directional benefit was measured using the HINT. In contrast, the results of the AV CST revealed that directional benefit was higher in the more-reverberant condition. Although the mSII model accurately predicted the HINT-measured directional benefit, the model using the American National Standards Institute correction equations underestimated the directional benefit measured using the AV CST in both reverberation conditions. Applying the newer equations, the model resulted in a more accurate prediction in the low-reverberation condition. However, AV directional benefit in the moderately reverberant condition was still underestimated. CONCLUSIONS: Hearing aid users would achieve the greatest directional benefit in situations in which they do not reach ceiling performance. The present study suggests that in the real world these situations may include face-to-face communication occurring in environments with higher reverberation. The opposite trends demonstrated by the HINT and AV CST highlight the importance of using ecologically valid laboratory testing to estimate the real-world effectiveness of a hearing aid and its technology. As a likely result of the difference in the effect on speech cues between noise and reverberation, the new equations developed from the low-reverberation booth failed to predict AV directional benefit in the more-reverberant environment. The mSII model with visual cue correction equations would be able to provide accurate predictions for AV directional benefit when the acoustic environments are similar to the ones used to derive the equations.

The Speech Intelligibility Index and the pure-tone average as predictors of lexical ability in children fit with hearing AIDS.

PURPOSE: To determine whether a clinically obtainable measure of audibility, the aided Speech Intelligibility Index (SII; American National Standards Institute, 2007), is more sensitive than the pure-tone average (PTA) at predicting the lexical abilities of children who wear hearing aids (CHA). METHOD: School-age CHA and age-matched children with normal hearing (CNH) repeated words and nonwords, learned novel words, and completed a standardized receptive vocabulary test. Analyses of covariance allowed comparison of the 2 groups. For CHA, regression analyses determined whether SII held predictive value over and beyond PTA. RESULTS: CHA demonstrated poorer performance than CNH on tests of word and nonword repetition and receptive vocabulary. Groups did not differ on word learning. Aided SII was a stronger predictor of word and nonword repetition and receptive vocabulary than PTA. After accounting for PTA, aided SII remained a significant predictor of nonword repetition and receptive vocabulary. CONCLUSIONS: Despite wearing hearing aids, CHA performed more poorly on 3 of 4 lexical measures. Individual differences among CHA were predicted by aided SII. Unlike PTA, aided SII incorporates hearing aid amplification characteristics and speech-frequency weightings and may provide a more valid estimate of the child's access to and ability to learn from auditory input in real-world environments.