A Central Auditory Test reveals differences between drug treatment regimens in adults living with HIV.

OBJECTIVE: This exploratory study examined whether central auditory tests show differences between people living with HIV (PLWH) treated with two predominant antiretroviral drug therapy (ART) regimens. DESIGN: Cross-sectional. STUDY SAMPLE: 253 PLWH (mean age 39.8 years) from the Shanghai Public Health Clinical Centre, China. METHODS: The Hearing in Noise Test speech reception threshold (SRT) assessed central auditory function and the Montreal Cognitive Assessment (MoCA) assessed cognition. The relationship between ART regimen and SRT was evaluated with multivariable linear regression incorporating age, HIV duration, and peripheral hearing ability. Multivariable logistic regression was used to ascertain if SRT and ART regimen predicted MoCA impairment. RESULTS: The two predominant ART regimens differed by one drug (zidovudine or tenofovir). Participants taking the zidovudine-containing regimen had poorer SRT performance (p=.012) independent of age and hearing thresholds. MoCA scores did not differ between drug regimens, but a negative relationship was found between SRT and MoCA impairment (p=.048). CONCLUSIONS: ART regimens differed in their association with central auditory test performance likely reflecting neurocognitive changes in PLWH taking the zidovudine-containing regimen. Central auditory test performance also marginally predicted cognitive impairment, supporting further assessment of central auditory tests to detect neurocognitive deficits in PLWH.

The Resting State Central Auditory Network: a Potential Marker of HIV-Related Central Nervous System Alterations.

OBJECTIVE: HIV positive (HIV+) individuals with otherwise normal hearing ability show central auditory processing deficits as evidenced by worse performance in speech-in-noise perception compared with HIV negative (HIV-) controls. HIV infection and treatment are also associated with lower neurocognitive screening test scores, suggesting underlying central nervous system damage. To determine how central auditory processing deficits in HIV+ individuals relate to brain alterations in the cortex involved with auditory processing, we compared auditory network (AN) functional connectivity between HIV+ adults with or without speech-in-noise perception difficulties and age-matched HIV- controls using resting-state fMRI. DESIGN: Based on the speech recognition threshold of the hearing-in-noise test, twenty-seven HIV+ individuals were divided into a group with speech-in-noise perception abnormalities (HIV+SPabnl, 38.2 ± 6.8 years; 11 males and 2 females) and one without (HIV+SPnl 34.4 ± 8.8 years; 14 males). An HIV- group with normal speech-in-noise perception (HIV-, 31.3 ± 5.2 years; 9 males and 3 females) was also enrolled. All of these younger and middle-aged adults had normal peripheral hearing determined by audiometry. Participants were studied using resting-state fMRI. Independent component analysis was applied to identify the AN. Group differences in the AN were identified using statistical parametric mapping. RESULTS: Both HIV+ groups had increased functional connectivity (FC) in parts of the AN including the superior temporal gyrus, middle temporal gyrus, supramarginal gyrus, and Rolandic operculum compared to the HIV- group. Compared with the HIV+SPnl group, the HIV+SPabnl group showed greater FC in parts of the AN including the middle frontal and inferior frontal gyri. CONCLUSIONS: The classical auditory areas in the temporal lobe are affected by HIV regardless of speech perception ability. Increased temporal FC in HIV+ individuals might reflect functional compensation to achieve normal primary auditory perception. Furthermore, increased frontal FC in the HIV+SPabnl group compared with the HIV+SPnl group suggest that speech-in-noise perception difficulties in HIV-infected adults also affect areas involved in higher-level cognition, providing imaging evidence consistent with the hypothesis that HIV-related neurocognitive deficits can include central auditory processing deficits.

Reference equivalent threshold sound pressure levels for the Wireless Automated Hearing Test System.

This paper presents reference equivalent threshold sound pressure levels (RETSPLs) for the Wireless Automated Hearing Test System (WAHTS), a recently commercialized device developed for use as a boothless audiometer. Two initial studies were conducted following the ISO 389-9 standard [ISO 389-9 (2009). "Acoustics-Reference zero for the calibration of audiometric equipment. Part 9: Preferred test conditions for the determinations of reference hearing threshold levels" (International Organization for Standardization, Geneva)]. Although the standard recruitment criteria are intended to yield otologically normal test subjects, the recruited populations appeared to have slightly elevated thresholds [5-10 dB hearing level (HL)]. Comparison of WAHTS thresholds to other clinical audiometric equipment revealed bias errors that were consistent with the elevated thresholds of the RETSPL populations. As the objective of RETSPLs is to ensure consistent thresholds regardless of the equipment, this paper presents the RETSPLs initially obtained following ISO 389-9:2009 and suggested correction to account for the elevated HLs of the originally recruited populations. Two additional independent studies demonstrate the validity of these corrected thresholds.

The German hearing in noise test.

OBJECTIVES: The aims of this study were to develop a German Hearing In Noise Test (HINT) using the same methodology as with previous HINT tests; to develop sentence lists for measuring speech reception thresholds (SRTs); and to determine test-retest reliability and norms for measures obtained under headphones. DESIGN: The following steps were followed: develop and record sentences, synthesise masking noise, determine the performance-intensity (PI) function, equalise sentence difficulty in the masking noise. Form sentence lists of equal difficulty. Measure SRTs for normal hearing individuals to determine practice/learning effects, test-retest reliability, and norms. STUDY SAMPLE: Three groups of adults (median age = 25 years) with average better ear pure-tone averages (PTAs) ≤ 5 dB HL participated. RESULTS: The 12 20-sentence lists were well-matched phonemically and did not differ significantly in difficulty. Test-retest reliability 95% confidence intervals ranged from 1.3 to 2.5 dB. Norms in quiet and in noise exhibited the same pattern as those for other HINT languages. German norms were approximately 2 dB lower than other languages in the noise conditions. CONCLUSIONS: The German HINT materials are comparable to those for other languages and are partially consistent with recommendations for construction of multilingual speech tests. They can be used for comparing and pooling research results from the international research community.

Development of hearing standards for Ontario's Constable Selection System.

Objective: Develop valid and defensible hearing standards for Ontario constables to ensure safe and efficient operations. Design: Research involved three steps: (1) identification of hearing critical (HC) tasks, (2) characterisation of real-world noise environments where these tasks are performed (3) and establishment of screening criteria and protocols for determining fitness for duty. Study sample: Three panels of subject matter experts (SMEs) from different Ontario police services participated in Steps 1 and 3. Result: Fifty-one HC tasks conducted in 25 different environments were identified. Acceptable levels of speech communication in noise were based on environments with the highest frequency, importance and difficulty ratings. The ability to understand soft speech was also deemed critical. These translated into a 2 dB maximum elevation in the Noise Composite speech recognition threshold (SRT) with the Hearing-In-Noise-Test and a threshold in quiet of 35 dBA or better. Conclusions: Speech communication modelling methodology greatly facilitates the task of developing fitness for duty hearing standards, but participation of SMEs is crucial for face validity.

Speech in Noise Perception as a Marker of Cognitive Impairment in HIV Infection.

OBJECTIVES: Human immunodeficiency virus positive (HIV+) individuals report hearing difficulties, but standard audiological tests show no, or small, changes in peripheral hearing ability. The hearing complaints may reflect central nervous system (CNS) auditory processing deficits, rather than middle or inner ear problems, and may result from CNS damage due to HIV infection or treatment. If central auditory task performance and cognitive deficits in HIV+ individuals are shown to be related, then central auditory tests might serve as a "window" into CNS function in these patients. DESIGN: We measured cognitive performance (Mandarin Montreal Cognitive Assessment [MoCA]) and speech in noise perception (Mandarin hearing-in-noise test [HINT]) in 166 normal-hearing HIV+ individuals (158 men, 8 women, average age 36 years) at the Shanghai Public Health Clinical Center in Shanghai, China. Data collection included audiometry, tympanometry, and the Amsterdam Inventory of Auditory Handicap (AIAH), which assesses the subjective ability to understand speech and localize sound. RESULTS: Subjects had no middle ear disease and met criteria for normal-hearing sensitivity (all thresholds 20 dB HL or less). A significant negative relationship between speech reception thresholds (SRT) and MoCA scores (r = 0.15, F = 28.2, p < 0.001) existed. Stepwise linear regression showed that when the factors of age, MoCA scores, hearing thresholds, and education level were considered, only age and MoCA scores contributed independently to the SRT results (overall model r = 0.30, F = 38.8, p < 0.001). Subjective hearing complaints from the AIAH supported the HINT results. AIAH and MoCA scores were also related (r = 0.05, F = 8.5, p = 0.004), with those with worse MoCA scores having more problems on the AIAH. When the cohort was divided into those with normal and abnormal performance on the MoCA, those with abnormal performance on the MoCA had significantly higher average SRTs (p < 0.001). CONCLUSIONS: Understanding speech in noise measured both objectively with the HINT and subjectively with the AIAH was inversely related to cognitive abilities despite a normal ability to hear soft sounds determined by audiometry. Although age was also an important independent factor affecting speech perception, the age relationship within the speech findings in this study may represent more than just age-related declines in speech in noise understanding. Although reliable data on disease duration are not available, the older members of this cohort likely had HIV longer and probably had more severe symptoms at presentation than the younger members because early detection and treatment of HIV in Shanghai has improved over time. Therefore, the age relationship may also include elements of disease duration and severity. Speech perception, especially in challenging listening conditions, involves cortical and subcortical centers and is a demanding neurological task. The problems interpreting speech in noise HIV+ individuals have may reflect HIV-related or HIV treatment-related, central nervous damage, suggesting that CNS complications in HIV+ individuals could potentially be diagnosed and monitored using central auditory tests.

Evidence-Based Occupational Hearing Screening I: Modeling the Effects of Real-World Noise Environments on the Likelihood of Effective Speech Communication.

OBJECTIVES: The objectives of this study were to (1) identify essential hearing-critical job tasks for public safety and law enforcement personnel; (2) determine the locations and real-world noise environments where these tasks are performed; (3) characterize each noise environment in terms of its impact on the likelihood of effective speech communication, considering the effects of different levels of vocal effort, communication distances, and repetition; and (4) use this characterization to define an objective normative reference for evaluating the ability of individuals to perform essential hearing-critical job tasks in noisy real-world environments. DESIGN: Data from five occupational hearing studies performed over a 17-year period for various public safety agencies were analyzed. In each study, job task analyses by job content experts identified essential hearing-critical tasks and the real-world noise environments where these tasks are performed. These environments were visited, and calibrated recordings of each noise environment were made. The extended speech intelligibility index (ESII) was calculated for each 4-sec interval in each recording. These data, together with the estimated ESII value required for effective speech communication by individuals with normal hearing, allowed the likelihood of effective speech communication in each noise environment for different levels of vocal effort and communication distances to be determined. These likelihoods provide an objective norm-referenced and standardized means of characterizing the predicted impact of real-world noise on the ability to perform essential hearing-critical tasks. RESULTS: A total of 16 noise environments for law enforcement personnel and eight noise environments for corrections personnel were analyzed. Effective speech communication was essential to hearing-critical tasks performed in these environments. Average noise levels, ranged from approximately 70 to 87 dBA in law enforcement environments and 64 to 80 dBA in corrections environments. The likelihood of effective speech communication at communication distances of 0.5 and 1 m was often less than 0.50 for normal vocal effort. Likelihood values often increased to 0.80 or more when raised or loud vocal effort was used. Effective speech communication at and beyond 5 m was often unlikely, regardless of vocal effort. CONCLUSIONS: ESII modeling of nonstationary real-world noise environments may prove an objective means of characterizing their impact on the likelihood of effective speech communication. The normative reference provided by these measures predicts the extent to which hearing impairments that increase the ESII value required for effective speech communication also decrease the likelihood of effective speech communication. These predictions may provide an objective evidence-based link between the essential hearing-critical job task requirements of public safety and law enforcement personnel and ESII-based hearing assessment of individuals who seek to perform these jobs.

Evidence-based occupational hearing screening II: validation of a screening methodology using measures of functional hearing ability.

OBJECTIVE: Validate use of the Extended Speech Intelligibility Index (ESII) for prediction of speech intelligibility in non-stationary real-world noise environments. Define a means of using these predictions for objective occupational hearing screening for hearing-critical public safety and law enforcement jobs. DESIGN: Analyses of predicted and measured speech intelligibility in recordings of real-world noise environments were performed in two studies using speech recognition thresholds (SRTs) and intelligibility measures. ESII analyses of the recordings were used to predict intelligibility. Noise recordings were made in prison environments and at US Army facilities for training ground and airborne forces. Speech materials included full bandwidth sentences and bandpass filtered sentences that simulated radio transmissions. STUDY SAMPLE: A total of 22 adults with normal hearing (NH) and 15 with mild-moderate hearing impairment (HI) participated in the two studies. RESULTS: Average intelligibility predictions for individual NH and HI subjects were accurate in both studies (r2 ≥ 0.94). Pooled predictions were slightly less accurate (0.78 ≤ r2 ≤ 0.92). CONCLUSIONS: An individual's SRT and audiogram can accurately predict the likelihood of effective speech communication in noise environments with known ESII characteristics, where essential hearing-critical tasks are performed. These predictions provide an objective means of occupational hearing screening.

Tone perception in Mandarin-speaking children with cochlear implants.

OBJECTIVE: To evaluate the effects of implant age and duration of implantation on development of Mandarin tone perception in paediatric cochlear implant recipients. DESIGN: Retrospective cross-sectional evaluation of tone perception, as assessed with the Mandarin Early Speech Perception test at 3, 6, 12, 24, 36 and 48 months after activation. STUDY SAMPLE: A total of 143 subjects, 60 girls and 83 boys unilaterally implanted at 1-4 years of age comprised the sample. All the subjects were implanted with devices from one of three manufacturers. RESULTS: Regardless of implant age, approximately 80% of the subjects obtained overall tone discrimination scores significantly above chance by 4 years after implantation, and average discrimination accuracy increased from approximately 68% to 79%. Acoustically distinct tones 1 and 4 were discriminated and recognised more accurately, while less distinct tones 2 and 3 were discriminated and recognised less accurately. Large individual differences in performance were evident. CONCLUSIONS: Most Mandarin-speaking paediatric CI recipients discriminate tones above chance at 5 years of age with accuracy comparable to that of children with normal hearing at 2 years of age. Modest benefits of early implantation are evident.

The effect of non-native and non-regional speech testing on a multi-lingual population.

OBJECTIVE: This study was conducted to evaluate the speech perception of Malaysian Chinese adults using the Taiwanese Mandarin HINT (MHINT-T) and the Malay HINT (MyHINT). DESIGN: The MHINT-T and the MyHINT were presented in quiet and noise (front, right and left) conditions under headphones. Results for the two tests were compared with each other and with the norms for each test. STUDY SAMPLE: Malaysian Chinese native speakers of Mandarin (N = 58), 18-31 years of age with normal hearing. RESULTS: On average, subjects demonstrated poorer speech perception ability than the normative samples for these tests. Repeated measures ANOVA showed that speech reception thresholds (SRTs) were slightly poorer on the MHINT-T than on the MyHINT for all test conditions. However, normalized SRTs were poorer by 0.6 standard deviations for MyHINT as compared with MHINT-T. CONCLUSIONS: MyHINT and MHINT-T can be used as norm-referenced speech perception measures for Mandarin-speaking Chinese in Malaysia.

The Norwegian Hearing in Noise Test for Children.

OBJECTIVES: The aims of this study were to create 12 ten-sentence lists for the Norwegian Hearing in Noise Test for children, and to use these lists to collect speech reception thresholds (SRTs) in quiet and in noise to assess speech perception in normal hearing children 5 to 13 years of age, to establish developmental trends, and to compare the results with those of adults. Data were collected in an anechoic chamber and in an audiometric test room, and the effect of slight room reverberation was estimated. DESIGN: The Norwegian Hearing in Noise Test for children was formed from a subset of the adult sentences. Selected sentences were repeatable by 5- and 6-year-old children in quiet listening conditions. Twelve sentence lists were created based on the sentences' phoneme distributions. Six-year-olds were tested with these lists to determine list equivalence. Slopes of performance intensity (PI) functions relating mean word scores and signal to noise ratios (SNRs) were estimated for a group of 7-year-olds and adults. HINT normative data were collected for 219 adults and children 5 to 13 years of age in anechoic and audiometric test rooms, using noise levels 55, 60, or 65 dBA. Target sentences always originated from the front; whereas, the noise was presented either from the front, noise front (NF), from the right, noise right (NR) or from the left, noise left (NL). The NR and NL scores were averaged to yield a noise side (NS) score. All 219 subjects were tested in the NF condition, and 95 in the NR and NL conditions. Retest of the NF at the end of the test session was done for 53 subjects. Longitudinal data were collected by testing 9 children as 6, 8, and 13 years old. RESULTS: NF and NS group means for adults were -3.7 and -11.8 dB SNR, respectively. Group means for 13-year-olds were -3.3 and -9.7, and for the 6-year-olds group means were -0.3 and -5.7 dB SNR, as measured in an anechoic chamber. NF SRTs measured in an audiometric test room were 0.7 to 1.5 higher (poorer) than in the anechoic chamber. Developmental trends were comparable in both rooms. PI slopes were 8.0% dB SNR for the 7-year-olds and 10.1% for the adults. NF SRTs in the anechoic chamber improved by 0.7 dB per year over an age range of 5 to 10 years. Using a PI slope 8 to 10% per dB, the estimated increase in percent intelligibility was 4 to 7% per year. Adult SRTs were about 3 dB lower than those for 6-year-olds, corresponding to 25 to 30% better intelligibility for adults. CONCLUSIONS: Developmental trends in HINT performance for Norwegian children with normal hearing are similar to those seen in other languages, including American English and Canadian French. SRTs approach adult normative values by the age of 13; however, the benefits of spatial separation of the speech and noise sources are less than those seen for adults.

Initial classification of pediatric hearing impairment using behavioral measures of early prelingual auditory development.

OBJECTIVE: Determine the sensitivity, specificity, and accuracy of pediatric hearing loss classification using behavioral evidence of early prelingual auditory development (EPLAD). Validate behavioral measures of EPLAD. DESIGN: EPLAD was assessed in a prospective sample of hearing-impaired children using the infant-toddler meaningful auditory integration scale (ITMAIS/MAIS). Hearing losses were classified using tone-burst auditory brainstem response (ABR) and ITMAIS/MAIS scores. This process was repeated in a second retrospective sample. STUDY SAMPLE: The prospective sample was comprised of 139 hearing-impaired children under five years of age. Approximately equal proportions of mild-moderate, severe, and profound losses were included. The second retrospective sample was comprised of case records for 144 hearing-impaired children meeting the same selection criteria. This sample contained more than 80% profound losses. RESULTS: EPLAD trajectories reached different asymptotes after two years of age, depending on the severity of hearing loss, allowing children over this age to be classified. The sensitivity of EPLAD classifications was over 90%; specificity was over 82%; and accuracy was over 88%. CONCLUSIONS: Behavioral evidence of EPLAD provides an initial means of classifying pediatric hearing losses which can facilitate initial treatment options prior to diagnostic evaluation with tone-burst ABR.

Quantification of the effects of Mandarin dialect differences on the use of norm-referenced speech perception tests.

OBJECTIVE: Determine the effects of Chinese dialects on results for the Mandarin HINT recorded with a talker speaking Standard Mandarin (Putonghua). DESIGN: Normally-hearing subjects with different dialect exposure histories and usage preferences were administered the Mandarin HINT, and results were compared with published norms. Additional published measures of the intelligibility and mutual intelligibility of Chinese dialects were used to identify dialects for which Putonghua is highly intelligible. STUDY SAMPLE: One sample (N = 19) was exposed to a variety of dialects throughout China during childhood, and used Putonghua as adults. A second sample (N = 22) was exposed to Sichuanhua (the dialect found in Sichuan province) during childhood, and used Sichuanhua as adults. RESULTS: The average difference in SRTs for the Putonghua and Sichuanhua groups was 0.66 dB, with the Sichuanhua group's SRTs slightly higher. Means for neither group fell outside the confidence intervals for the norms. Putonghua is intelligible for 98% of Sichuanhua dialect users, and for over 90% of the users of two-thirds of the remaining Chinese regional dialects. CONCLUSIONS: Norm-referenced speech perception tests, such as the Mandarin HINT, can be used with speakers of Chinese regional dialects for whom Putonghua is highly intelligible. Small differences in dialect-specific norms are not clinically significant.

The effect of interleaved filters on normal hearing listeners' perception of binaural cues.

OBJECTIVES: Hearing-impaired individuals often have difficulty in noisy environments. Interleaved filters, where signals from neighboring frequency regions are sent to opposite ears, may benefit those individuals but may also reduce the benefits of spatial cues. This study investigated the effect of interleaved filters on the use of spatial cues. DESIGN: Normal-hearing subjects' sound localization abilities were tested with and without interleaved filters. RESULTS: Participants' localization performance was worse with interleaved filters but better than chance. Interleaving in high-frequency regions primarily affected interaural level difference cues, and interleaving in low-frequency regions primarily affected interaural time difference cues. CONCLUSIONS: Interleaved filters reduced but did not eliminate the benefits of spatial cues. The effect was dependent on the frequency region they were used in, indicating that it may be possible to use interleaved filters in a subset of frequency regions to selectively preserve different binaural cues.

Development of the Turkish hearing in noise test for children.

Objectives: The aim of this study is to develop the Turkish version of hearing in noise test for children (HINT-C) by providing norms and correction factors for the children in different age groups.Methods: A total of 77 individuals with normal hearing - 62 children (6-12 years old) and 15 adults (18-30 years old) - were included. Twelve phonemically balanced 10-sentence lists were created from the adult version of the Turkish HINT (Study 1). Age-specific norms, correction factors and maturation effects were examined using the Turkish HINT-C (Study 2).Results: Mean performances under different listening conditions and Spatial Release from Masking (SRM) advantage values were obtained for the 6-, 8-, 10-, and 12-year-old and estimated for the 7-, 9-, and 11-year-old age groups, and correction factors were calculated for all children age groups. Turkish-speaking children did not achieve adult-like hearing in noise performance, until they were 12 years old.Conclusions: Twelve phonemically balanced 10-sentence lists of Turkish HINT-C were created, and the mean performances of children in different age groups were measured. In addition to the age-specific HINT-C norms and correction factors for the 6-, 8-, 10-, and 12-year-old age groups, the maturation effects were determined.Highlights The assessment of speech-in-noise perception is highly critical for children.To evaluate the speech-in-noise perception ability, 12 phonemically balanced 10-sentence lists of Turkish HINT-C were created.Speech-in-noise perception ability improves with age.Turkish-speaking children do not achieve adult-like hearing in noise performance, until they were 12 years old.

Characterization of speech understanding in various types of noise.

This study examined (1) the effects of noise on speech understanding and (2) whether performance in real-life noises could be predicted based on performance in steady-state speech-spectrum-shaped noise. The noise conditions included a steady-state speech-spectrum-shaped noise and six types of real-life noise. Thirty normal-hearing adults were tested using sentence materials from the Cantonese Hearing In Noise Test (CHINT). To achieve the first aim, the performance-intensity function slopes in these noise conditions were estimated and compared. Variations in performance-intensity function slopes were attributed to differences in the amount of amplitude fluctuations and the presence of competing background speech. How well the data obtained in real-life noises fit the performance-intensity functions obtained in steady-state speech-spectrum-shaped noises was examined for the second aim of the study. Four out of six types of noise yielded performance-intensity function slopes similar to that in steady-state speech-spectrum-shaped noise. After accounting for individual differences in sentence reception threshold (SRT) and the offset between the signal-to-noise ratio for 50% intelligibility across different types of noise, performance in steady-state speech-spectrum-shaped noise was found to predict well the performance in most of the real-life noise conditions.

Cochlear implant patients' localization using interaural level differences exceeds that of untrained normal hearing listeners.

Bilateral cochlear implant patients are unable to localize as well as normal hearing listeners. Although poor sensitivity to interaural time differences clearly contributes to this deficit, it is unclear whether deficits in terms of interaural level differences are also a contributing factor. In this study, localization was tested while manipulating interaural time and level cues using head-related transfer functions. The results indicate that bilateral cochlear implant users' ability to localize based on interaural level differences is actually greater than that of untrained normal hearing listeners.

Outcome assessment alternatives for young children during the first 12 months after pediatric hearing-aid fittings.

OBJECTIVE: Perform longitudinal evaluations of young children during the first 12 months after initial hearing-aid fitting. Document evidence of early prelingual auditory development (EPLAD), identify factors that affect EPLAD, and define performance milestones that can guide best practices. DESIGN: Unblinded, prospective, within-subject, repeated-measures design. Audiological measures and measures of EPLAD were taken at baseline, 3, 6, and 12 months after hearing-aid fitting. STUDY SAMPLE: Subjects were 45 pediatric patients initially fitted with hearing aids between 1 and 5.5 years of age. Four groups were formed for analysis purposes based on severity of hearing loss (moderate-to-severe and profound) and initial fitting age (≤ 30 months and > 30 months). RESULTS: All groups exhibited statistically significant increases in EPLAD within six months of hearing-aid fitting, and those with profound losses exhibited further statistically significant improvement between six and 12 months. Similar EPLAD levels were reached at 12 months regardless of severity of hearing loss. The EPLAD trajectory is similar to that following early cochlear implantation. CONCLUSIONS: Measures of EPLAD provide a means of evaluating outcomes following early pediatric hearing-aid intervention, supplementing behavioral audiological measures.

The relationship between high-frequency pure-tone hearing loss, hearing in noise test (HINT) thresholds, and the articulation index.

BACKGROUND: Speech recognition in noise testing has been conducted at least since the 1940s (Dickson et al, 1946). The ability to recognize speech in noise is a distinct function of the auditory system (Plomp, 1978). According to Kochkin (2002), difficulty recognizing speech in noise is the primary complaint of hearing aid users. However, speech recognition in noise testing has not found widespread use in the field of audiology (Mueller, 2003; Strom, 2003; Tannenbaum and Rosenfeld, 1996). The audiogram has been used as the "gold standard" for hearing ability. However, the audiogram is a poor indicator of speech recognition in noise ability. PURPOSE: This study investigates the relationship between pure-tone thresholds, the articulation index, and the ability to recognize speech in quiet and in noise. RESEARCH DESIGN: Pure-tone thresholds were measured for audiometric frequencies 250-6000 Hz. Pure-tone threshold groups were created. These included a normal threshold group and slight, mild, severe, and profound high-frequency pure-tone threshold groups. Speech recognition thresholds in quiet and in noise were obtained using the Hearing in Noise Test (HINT) (Nilsson et al, 1994; Vermiglio, 2008). The articulation index was determined by using Pavlovic's method with pure-tone thresholds (Pavlovic, 1989, 1991). STUDY SAMPLE: Two hundred seventy-eight participants were tested. All participants were native speakers of American English. Sixty-three of the original participants were removed in order to create groups of participants with normal low-frequency pure-tone thresholds and relatively symmetrical high-frequency pure-tone threshold groups. The final set of 215 participants had a mean age of 33 yr with a range of 17-59 yr. DATA COLLECTION AND ANALYSIS: Pure-tone threshold data were collected using the Hughson-Weslake procedure. Speech recognition data were collected using a Windows-based HINT software system. Statistical analyses were conducted using descriptive, correlational, and multivariate analysis of covariance (MANCOVA) statistics. RESULTS: The MANCOVA analysis (where the effect of age was statistically removed) indicated that there were no significant differences in HINT performances between groups of participants with normal audiograms and those groups with slight, mild, moderate, or severe high-frequency hearing losses. With all of the data combined across groups, correlational analyses revealed significant correlations between pure-tone averages and speech recognition in quiet performance. Nonsignificant or significant but weak correlations were found between pure-tone averages and HINT thresholds. CONCLUSIONS: The ability to recognize speech in steady-state noise cannot be predicted from the audiogram. A new classification scheme of hearing impairment based on the audiogram and the speech reception in noise thresholds, as measured with the HINT, may be useful for the characterization of the hearing ability in the global sense. This classification scheme is consistent with Plomp's two aspects of hearing ability (Plomp, 1978).

Technology-limited and patient-derived versus audibility-derived fittings in bone-anchored hearing aid users: a validation study.

OBJECTIVES: Current approaches to fit bone-anchored hearing aid (Baha) rely heavily on patient feedback of "loudness" and "sound quality." Audiologists are limited to this approach for two reasons: (1) the technology in current models of Baha does not allow for much fine-tuning of frequency response or maximum output on an individual basis and (2) there has not been a valid approach to verify the frequency response or maximum output on an individual basis. The objectives of this study are to (1) describe an alternative approach to fit Baha, an "audibility-derived (AD)" fitting, and (2) test whether outcomes improve with this new fitting compared with the current "patient-derived (PD)" fitting. DESIGN: This study used a repeated measures design where each subject experienced both the AD and PD fittings in random order. Subjects were tested on a variety of outcome measures including output levels of aided speech, hearing in noise test (quiet and in noise), consonant recognition in noise, aided loudness, and subjective percentage of words understood. RESULTS: Electromechanical testing revealed significantly higher aided output with the AD fitting, especially in the high frequencies. Subjects performed significantly better in all outcome measures with the AD fitting approach except when testing aided loudness and subjective perception for which the differences were nonsignificant. When the input levels to the Baha were soft, advantages for the AD fitting were emerging on these tests, but they did not reach significance. CONCLUSIONS: This study presents a more objective, fitting approach for Baha that leads to better outcomes in the laboratory. The next steps will be to test these fittings in the real world and to make the approach generally available to clinicians fitting Bahas.