A double-blind, randomized controlled trial exploring the efficacy of frequency lowering hearing aids in patients with high-frequency hearing loss.

OBJECTIVE: Whether linear frequency transposition (LFT) assists individuals with hearing difficulties has been studied for years, but no reliable comparison between LFT hearing aids (HAs) and conventional compression-type HAs has been conducted. Herein, we report on the first, relevant, double-blind, randomized controlled trial on this topic using a large sample size. We compared the efficacies of LFT HAs to those of compression-type HAs in patients with high-frequency hearing loss (HFHL); we also reviewed the literature. METHODS: A total of 103 patients were randomized into three groups: conventional HAs featuring wide dynamic range compression (control group); HAs featuring LFT (LFT group); and HAs employing both LFT and wide dynamic range compression of high frequencies (combined group). Pure tone averages (PTAs), speech recognition thresholds (SRTs), word recognition scores (WRSs), and Abbreviated Profile of Hearing Aid Benefit (APHAB) inventories were assessed at the initial visit and after 3 months of HA use. Subject preferences in terms of continued use of their HAs were also evaluated. RESULTS: The PTA, SRT, and WRS scores significantly improved in all three groups. No significant among-group differences were evident. The APHAB score significantly improved only in the control group; HA future-use preference was also highest in this group. CONCLUSION: LFT did not provide an additional benefit for subjects with HFHL over conventional amplification and users preferred conventional HAs featuring wide dynamic range compression.

Hearing Outcome of Low-tone Compared to High-tone Sudden Sensorineural Hearing Loss

Abstract Introduction Low-tone sudden sensorineural hearing loss (SSHL) is a well-recognized disease, in which the hearing loss is restricted to low frequencies. In contrast to lowtone SSHL, high-tone SSHL is characterized by high-frequency (4,000, 8,000 Hz) hearing loss and preservation of low-, middle-frequency hearing. Objective The objective of this study is to compare the hearing recovery and longterm outcome of low-tone SSHL with those of patients affected by high-tone SSHL in a follow-up of ~ 3 years. Methods The low-tone SSHL and high-tone SSHL groups included 27 and 20 patients, respectively; the patients of both groups were treated with intravenous steroids. Predictive factors (gender, affected side, delay of treatment, follow-up time) were also examined. Results Overall, complete hearing recovery was observed in 77.7% of the patients in the low-tone SSHL group and in 15% of the patients in the high-tone SSHL group. In the high-tone SSHL group, a higher proportion of patients reported tinnitus compared with the low-tone SSHL group (13 cases [65%] versus 3 cases [11%]); however, recurrences were more common in the low-tone SSHL (22%, 6 patients) compared with the hightone SSHL (2 cases [10%]) group. No predictive factor was found to statistically impact on hearing outcome. Conclusion After initial therapy, the low-tone SSHL patients have more favorable hearing outcome than high-tone SSHL patients. However, recurrences occurred more frequently in the low-tone SSHL group, while the high-tone SSHL group was more often accompanied by residual symptoms, such as tinnitus. (AU)

Open-Fit Domes and Children with Bilateral High-Frequency Sensorineural Hearing Loss: Benefits and Outcomes.

BACKGROUND: Open-fit domes (OFDs) coupled with behind-the-ear (BTE) hearing aids were designed for adult listeners with moderate-to-severe bilateral high-frequency hearing loss (BHFL) with little to no concurrent loss in the lower frequencies. Adult research shows that BHFL degrades sound localization accuracy (SLA) and that BTE hearing aids with conventional earmolds (CEs) make matters worse. In contrast, research has shown that OFDs enhance spatial hearing percepts in adults with BHFL. Although the benefits of OFDs have been studied in adults with BHFL, no published studies to date have investigated the use of OFDs in children with the same hearing loss configuration. This study seeks to use SLA measurements to assess efficacy of bilateral OFDs in children with BHFL. PURPOSE: To measure SLA in children with BHFL to determine the extent to which hearing loss, age, duration of CE use, and OFDs affect localization accuracy. RESEARCH DESIGN: A within-participant experimental design using repeated measures was used to determine the effect of OFDs on localization accuracy in children with BHFL. A between-participant experimental design was used to compare localization accuracy between children with BHFL and age-matched controls with normal hearing (NH). STUDY SAMPLE: Eighteen children with BHFL who used CE and 18 age-matched NH controls. Children in both groups were divided into two age groups: older children (10-16 yr) and younger children (6-9 yr). DATA COLLECTION AND ANALYSIS: All testing was done in a sound-treated booth with a horizontal array of 15 loudspeakers (radius of 1 m). The stimulus was a spondee word, "baseball": the level averaged 60 dB SPL and randomly roved (±8 dB). Each child was asked to identify the location of a sound source. Localization error was calculated across the loudspeaker array for each listening condition. RESULTS: A significant interaction was found between immediate benefit from OFD and duration of CE usage. Longer CE usage was associated with degraded localization accuracy using OFDs. Regardless of chronological age, children who had used CEs for <6 yr showed immediate localization benefit using OFDs, whereas children who had used CEs for >6 yr showed immediate localization interference using OFDs. Development, however, may play a role in SLA in children with BHFL. When unaided, older children had significantly better localization acuity than younger children with BHFL. When compared to age-matched controls, children with BHFL of all ages showed greater localization error. Nearly all (94% [17/18]) children with BHFL spontaneously reported immediate own-voice improvement when using OFDs. CONCLUSIONS: OFDs can provide sound localization benefit to younger children with BHFL. However, immediate benefit from OFDs is reduced by prolonged use of CEs. Although developmental factors may play a role in improving localization abilities over time, children with BHFL will rarely equal that of peers without early use of minimally disruptive hearing aid technology. Also, the occlusion effect likely impacts children far more than currently thought.

Cochlear Implantation in Children with Postlingual Progressive Steeply Sloping High-Frequency Hearing Loss.

BACKGROUND: Children with steeply sloping sensorineural hearing loss (SNHL) lack access to critical high-frequency cues despite the use of advanced hearing aid technology. In addition, their auditory-only aided speech perception abilities often meet Food and Drug Administration criteria for cochlear implantation. PURPOSE: The objective of this study was to describe hearing preservation and speech perception outcomes in a group of young children with steeply sloping SNHL who received a cochlear implant (CI). RESEARCH DESIGN: Retrospective case series. STUDY SAMPLE: Eight children with steeply sloping postlingual progressive SNHL who received a unilateral traditional CI at Seattle Children's Hospital between 2009 and 2013 and had follow-up data available up to 24 mo postimplant were included. DATA COLLECTION AND ANALYSIS: A retrospective chart review was completed. Medical records were reviewed for demographic information, preoperative and postoperative behavioral hearing thresholds, and speech perception scores. Paired t tests were used to analyze speech perception data. Hearing preservation results are reported. RESULTS: Rapid improvement of speech perception scores was observed within the first month postimplant for all participants. Mean monosyllabic word scores were 76% and mean phoneme scores were 86.7% at 1-mo postactivation compared to mean preimplant scores of 19.5% and 31.0%, respectively. Hearing preservation was observed in five participants out to 24-mo postactivation. Two participants lost hearing in both the implanted and unimplanted ear, and received a sequential bilateral CI in the other ear after progression of the hearing loss. One participant had a total loss of hearing in only the implanted ear. Results reported in this article are from the ear implanted first. Bilateral outcomes are not reported. CONCLUSIONS: CIs provided benefit for children with steeply sloping bilateral hearing loss for whom hearing aids did not provide adequate auditory access. In our cohort, significant improvements in speech understanding occurred rapidly postactivation. Preservation of residual hearing in children with a traditional CI electrode is possible.

The Effect of Adaptive Nonlinear Frequency Compression on Phoneme Perception.

PURPOSE: This study implemented a fitting method, developed for use with frequency lowering hearing aids, across multiple testing sites, participants, and hearing aid conditions to evaluate speech perception with a novel type of frequency lowering. METHOD: A total of 8 participants, including children and young adults, participated in real-world hearing aid trials. A blinded crossover design, including posttrial withdrawal testing, was used to assess aided phoneme perception. The hearing aid conditions included adaptive nonlinear frequency compression (NFC), static NFC, and conventional processing. RESULTS: Enabling either adaptive NFC or static NFC improved group-level detection and recognition results for some high-frequency phonemes, when compared with conventional processing. Mean results for the distinction component of the Phoneme Perception Test (Schmitt, Winkler, Boretzki, & Holube, 2016) were similar to those obtained with conventional processing. CONCLUSIONS: Findings suggest that both types of NFC tested in this study provided a similar amount of speech perception benefit, when compared with group-level performance with conventional hearing aid technology. Individual-level results are presented with discussion around patterns of results that differ from the group average.

Evaluation of a Frequency-Lowering Algorithm for Adults With High-Frequency Hearing Loss.

The objective was to determine the effects of a frequency-lowering algorithm (frequency composition, Fcomp) on consonant identification, word-final /s, z/ detection, the intelligibility of sentences in noise, and subjective benefit, for people with high-frequency hearing loss, including people with dead regions (DRs) in the cochlea. A single-blind randomized crossover design was used. Performance with Bernafon Acriva 9 hearing aids was compared with Fcomp off and Fcomp on. Participants wore the hearing aids in each condition in a counterbalanced order. Data were collected after at least 8 weeks of experience with a condition. Outcome measures were audibility, scores from the speech perception tests, and scores from a questionnaire comparing self-perceived hearing ability with Fcomp off and Fcomp on. Ten adults with mild to severe high-frequency hearing loss (seven with extensive DRs, one with patchy or restricted DRs, and two with no DR) were tested. Fcomp improved the audibility of high-frequency sounds for 6 out of 10 participants. There was no overall effect of Fcomp on consonant identification, but the pattern of consonant confusions varied across conditions and participants. For word-final /s, z/ detection, performance was significantly better with Fcomp on than with Fcomp off. Questionnaire scores showed no differences between conditions. In summary, Fcomp improved word-final /s, z/ detection. No benefit was found for the other measures.

Speech perception and quality of life of open-fit hearing aid users.

OBJECTIVE: To relate the performance of individuals with hearing loss at high frequencies in speech perception with the quality of life before and after the fitting of an open-fit hearing aid (HA). METHODS: The WHOQOL-BREF had been used before the fitting and 90 days after the use of HA. The Hearing in Noise Test (HINT) had been conducted in two phases: (1) at the time of fitting without an HA (situation A) and with an HA (situation B); (2) with an HA 90 days after fitting (situation C). STUDY SAMPLE: Thirty subjects with sensorineural hearing loss at high frequencies. RESULTS: By using an analysis of variance and the Tukey's test comparing the three HINT situations in quiet and noisy environments, an improvement has been observed after the HA fitting. The results of the WHOQOL-BREF have showed an improvement in the quality of life after the HA fitting (paired t-test). The relationship between speech perception and quality of life before the HA fitting indicated a significant relationship between speech recognition in noisy environments and in the domain of social relations after the HA fitting (Pearson's correlation coefficient). CONCLUSIONS: The auditory stimulation has improved speech perception and the quality of life of individuals.

Speech perception and quality of life of open-fit hearing aid users

ABSTRACT Objective To relate the performance of individuals with hearing loss at high frequencies in speech perception with the quality of life before and after the fitting of an open-fit hearing aid (HA). Methods The WHOQOL-BREF had been used before the fitting and 90 days after the use of HA. The Hearing in Noise Test (HINT) had been conducted in two phases: (1) at the time of fitting without an HA (situation A) and with an HA (situation B); (2) with an HA 90 days after fitting (situation C). Study Sample Thirty subjects with sensorineural hearing loss at high frequencies. Results By using an analysis of variance and the Tukey’s test comparing the three HINT situations in quiet and noisy environments, an improvement has been observed after the HA fitting. The results of the WHOQOL-BREF have showed an improvement in the quality of life after the HA fitting (paired t-test). The relationship between speech perception and quality of life before the HA fitting indicated a significant relationship between speech recognition in noisy environments and in the domain of social relations after the HA fitting (Pearson’s correlation coefficient). Conclusions The auditory stimulation has improved speech perception and the quality of life of individuals.

The effects of frequency lowering on speech perception in noise with adult hearing-aid users.

OBJECTIVE: Frequency lowering (FL) strategies move high frequency sound into a lower frequency range. This study determined if speech perception differences are observed between some of the different frequency lowering strategies that are available. DESIGN: A cross-sectional, repeated-measures design was used to compare three hearing aids that used wide-dynamic range compression (WDRC) and either non-linear frequency compression (NFC), linear frequency transposition (LFT), or frequency translation (FT). The hearing aids were matched to prescriptive real ear targets for WDRC. The settings for each FL strategy were adjusted to provide audibility for a 6300 Hz filtered speech signal. Sentence recognition in noise, subjective measures of sound quality, and a modified version of the speech intelligibility index (SII) were measured. STUDY SAMPLE: Ten adults between the ages of 63 to 82 years with bilateral, high frequency hearing loss. RESULTS: LFT and FT led to poorer sentence recognition compared to WDRC for most individuals. No difference in sentence recognition occurred with and without NFC. The quality questionnaire and SII showed few differences between conditions. CONCLUSION: Under similar fitting and testing conditions of this study, FL techniques may not provide speech understanding benefit in certain background noise situations.

Harmonic Frequency Lowering: Effects on the Perception of Music Detail and Sound Quality.

A novel algorithm for frequency lowering in music was developed and experimentally tested in hearing-impaired listeners. Harmonic frequency lowering (HFL) combines frequency transposition and frequency compression to preserve the harmonic content of music stimuli. Listeners were asked to make judgments regarding detail and sound quality in music stimuli. Stimuli were presented under different signal processing conditions: original, low-pass filtered, HFL, and nonlinear frequency compressed. Results showed that participants reported perceiving the most detail in the HFL condition. In addition, there was no difference in sound quality across conditions.

Relationship Among Signal Fidelity, Hearing Loss, and Working Memory for Digital Noise Suppression.

OBJECTIVES: This study considered speech modified by additive babble combined with noise-suppression processing. The purpose was to determine the relative importance of the signal modifications, individual peripheral hearing loss, and individual cognitive capacity on speech intelligibility and speech quality. DESIGN: The participant group consisted of 31 individuals with moderate high-frequency hearing loss ranging in age from 51 to 89 years (mean = 69.6 years). Speech intelligibility and speech quality were measured using low-context sentences presented in babble at several signal-to-noise ratios. Speech stimuli were processed with a binary mask noise-suppression strategy with systematic manipulations of two parameters (error rate and attenuation values). The cumulative effects of signal modification produced by babble and signal processing were quantified using an envelope-distortion metric. Working memory capacity was assessed with a reading span test. Analysis of variance was used to determine the effects of signal processing parameters on perceptual scores. Hierarchical linear modeling was used to determine the role of degree of hearing loss and working memory capacity in individual listener response to the processed noisy speech. The model also considered improvements in envelope fidelity caused by the binary mask and the degradations to envelope caused by error and noise. RESULTS: The participants showed significant benefits in terms of intelligibility scores and quality ratings for noisy speech processed by the ideal binary mask noise-suppression strategy. This benefit was observed across a range of signal-to-noise ratios and persisted when up to a 30% error rate was introduced into the processing. Average intelligibility scores and average quality ratings were well predicted by an objective metric of envelope fidelity. Degree of hearing loss and working memory capacity were significant factors in explaining individual listener's intelligibility scores for binary mask processing applied to speech in babble. Degree of hearing loss and working memory capacity did not predict listeners' quality ratings. CONCLUSIONS: The results indicate that envelope fidelity is a primary factor in determining the combined effects of noise and binary mask processing for intelligibility and quality of speech presented in babble noise. Degree of hearing loss and working memory capacity are significant factors in explaining variability in listeners' speech intelligibility scores but not in quality ratings.

Effects of Nonlinear Frequency Compression on ACC Amplitude and Listener Performance.

OBJECTIVES: Nonlinear frequency compression is a signal processing technique used to increase the audibility of high-frequency speech sounds for hearing aid users with sloping, high-frequency hearing loss. However, excessive compression ratios may reduce spectral contrast between sounds and negatively impact speech perception. This is of particular concern in infants and young children who may not be able to provide feedback about frequency compression settings. This study explores the use of an objective cortical auditory evoked potential that is sensitive to changes in spectral contrast, the acoustic change complex (ACC), in the verification of frequency compression parameters. DESIGN: ACC responses were recorded from adult listeners to a spectral ripple contrast stimulus that was processed using a range of frequency compression ratios (1:1, 1.5:1, 2:1, 3:1, and 4:1). Vowel identification, consonant identification, speech recognition in noise (QuickSIN), and behavioral ripple discrimination thresholds were also measured under identical frequency compression conditions. In Experiment 1, these tasks were completed in 10 adults with normal hearing. In Experiment 2, these same tasks were repeated in 10 adults with sloping, high-frequency hearing loss. RESULTS: Repeated measures analysis of variance was completed for each task and each group with frequency compression ratio as the within-subjects factor. Increasing the compression ratio did not affect vowel identification for the normal hearing group but did cause a significant decrease in vowel identification for the hearing-impaired listeners. Increases in compression ratio were associated with significant decrements in ACC amplitudes, consonant identification scores, ripple discrimination thresholds, and speech perception in noise scores for both groups of listeners. CONCLUSIONS: The ACC response, like speech and nonspeech perceptual measures, is sensitive to frequency compression ratio. Additional study is needed to establish optimal stimulus and recording parameters for the clinical application of this measure in the verification of hearing aid frequency compression settings.

Optimization of frequency lowering algorithms for getting the highest speech intelligibility improvement by hearing loss simulation.

High frequency hearing loss is a growing problem for both children and adults. To overcome this impairment, different frequency lowering methods (FLMs) were tried from 1930s, however no satisfaction was provided up to now. In this study, for getting higher speech intelligibility, eight combinations of FLMs which were designed originally were tried with simulated sounds onto normal hearing subjects. These improvements were calculated by the difference with standard hearing aid method, amplification. High frequency hearing loss was simulated with the combined suprathreshold effects. An offline study was carried out for each subject for determining the significant methods used in modified rhyme test (MRT) (Subjective measure for intelligibility). Significant methods were determined according to their speech intelligibility index (SII) (Objective measure for intelligibility). All different cases were tried under four noisy environments and a noise free environment. Twelve hearing impaired subjects were simulated by hearing loss simulation (HLS). MRT was developed for Turkish language as a first time. As the results of improvements, total 71 cases were statistically significant for twelve subjects. Eighty-three percent success of FLMs was achieved against amplification for being an alternative method of amplification in noisy environments. For four subjects, all significant methods gave higher improvements than amplification. As conclusion, specific method recommendations for different noisy environments were done for each subject for getting more speech intelligibility.

Evaluation of wideband frequency responses and non-linear frequency compression for children with mild to moderate high-frequency hearing loss.

OBJECTIVE: To evaluate wideband amplification and non-linear frequency compression (NLFC) as a means to improve speech recognition for children with mild/moderate hearing loss. DESIGN: Randomized within-subject design with repeated measures across test conditions. STUDY SAMPLE: Eleven children with mild to moderate hearing loss were evaluated with: (1) Phonak BTE without NLFC, (2) Phonak BTE with NLFC, and (3) Oticon BTE with wideband response extending to 8000 Hz. RESULTS: Use of NLFC provided better detection and recognition of high-frequency stimuli (e.g. /sh/ and /s/). No difference in performance between conditions was observed for speech recognition when measured with the University of Western Ontario (UWO) plurals test and the UWO distinctive features difference test. Finally, there were no differences between conditions on the BKB-SIN test. CONCLUSIONS: Children with mild to moderate hearing loss have good access to high-frequency phonemes presented at fixed levels (e.g. 50 to 60 dBA) with both wideband and NLFC technology. Similarly, sentence recognition in noise was similar with wideband and NLFC. Adaptive test procedures that probe performance at lower input levels showed small but significant improvements in the detection and recognition of the phonemes /s/ and /sh/ with NLFC condition when compared to the NLFC Off and wideband conditions.

Predictors of aided speech recognition, with and without frequency compression, in older adults.

OBJECTIVE: The aim was to investigate whether cognitive and/or audiological measures predict aided speech recognition, both with and without frequency compression (FC). DESIGN: Participants wore hearing aids, with and without FC for a total of 12 weeks (six weeks in each signal processing condition, ABA design). Performance on a sentence-in-noise recognition test was assessed at the end of each six-week period. Audiological (severity of high frequency hearing loss, presence of dead regions) and cognitive (reading span and trail making test scores) measures were obtained and assessed as predictors of sentence-in-noise recognition with and without FC enabled. STUDY SAMPLE: Twelve experienced hearing-aid users (aged 65-84 years old) with moderate-to-severe high-frequency hearing loss took part in the study. RESULTS: The results suggest that both auditory and cognitive factors can be predictive of sentence-in-noise recognition with conventional amplification. However, only auditory factors were significantly correlated with the degree of benefit obtained from FC. CONCLUSIONS: The strongest predictor of aided speech recognition, both with and without FC, was high frequency hearing loss. Cognitive performance was also a predictor of benefit from conventional amplification, but not of additional benefit from the use of FC.

Benefit from, and acclimatization to, frequency compression hearing aids in experienced adult hearing-aid users.

OBJECTIVE: The aim was to investigate whether frequency compression (FC) hearing aids provide additional benefit to that conferred by conventional amplification. DESIGN: Participants wore the same hearing aid with FC enabled and disabled for six weeks (ABA design) in each condition. Speech recognition tests (in both quiet and in noise) were administered alongside two questionnaires. Performance was compared across the two signal processing conditions and at different time points. STUDY SAMPLE: Twelve experienced hearing-aid users (aged 65-84 years old) with moderate-to-severe high-frequency hearing loss participated in the study. RESULTS: FC resulted in statistically significantly higher mean scores in all of the administered speech tests. Improvements over time were limited to high frequency phoneme perception. No effect of FC on self-report outcomes was observed. CONCLUSIONS: FC may lead to significant improvements in speech perception outcomes in both quiet and noise for many individuals. No participant was significantly disadvantaged by the use of FC.

[Speech perception with hearing aids in comparison to pure-tone hearing loss]. / Sprachverstehen mit Hörgeräten in Abhängigkeit vom Tongehör.

BACKGROUND AND AIM: Speech perception is the most important social task of the auditory system. Consequently, speech audiometry is essential to evaluate hearing aid benefit. The aim of the study was to describe the correlation between pure-tone hearing loss and speech perception. In particular, pure-tone audiogram, speech audiogram, and speech perception with hearing aids were compared. MATERIALS AND METHODS: In a retrospective study, 102 hearing aid users with bilateral sensorineural hearing loss were included. Pure-tone loss (PTA) was correlated to monosyllabic perception at 65 dB with hearing aid and with maximum monosyllabic perception with headphones. RESULTS: Speech perception as a function of hearing loss can be represented by a sigmoid function. However, for higher degrees of hearing loss, substantial deviations are observed. Maximum monosyllabic perception with headphones is usually not achieved with hearing aids at standard speech levels of 65 dB. CONCLUSION: For larger groups, average pure-tone hearing loss and speech perception correlate significantly. However, prognosis for individuals is not possible. In particular for higher degrees of hearing loss substantial deviations could be observed. Speech performance with hearing aids cannot be predicted sufficiently from speech audiograms. Above the age of 80, speech perception is significantly worse.

Benefit from non-linear frequency compression hearing aids in a clinical setting: the effects of duration of experience and severity of high-frequency hearing loss.

OBJECTIVES: To determine whether non-linear frequency compression (NLFC) is effective for hearing-impaired adults in a clinical setting. To determine whether benefit from NLFC is related to duration of NLFC experience or severity of high-frequency hearing loss. DESIGN: Participants were fitted with Phonak frequency compression hearing aids as part of their standard clinical care, using the manufacturer's default fitting settings. Participants had been using NLFC for between 1 and 121 weeks at the time of testing. Speech recognition thresholds in noise and consonant recognition in quiet were measured with and without NLFC enabled. STUDY SAMPLE: Forty-six experienced adult hearing-aid users. RESULTS: Consonant recognition in quiet, but not speech recognition in noise was significantly better with NLFC enabled. There was no significant correlation between duration of frequency compression experience and benefit. Benefit for consonant recognition was negatively correlated with mean audiometric thresholds from 2-6 kHz. CONCLUSIONS: NLFC was beneficial for consonant recognition but not speech recognition in noise. There was no evidence to support the idea that a long period of acclimatization is necessary to gain full benefit. The relation between benefit and high-frequency thresholds might be explained by the poor audibility of compressed information for some listeners with severe loss.

The influence of audibility on speech recognition with nonlinear frequency compression for children and adults with hearing loss.

OBJECTIVE: The primary goal of nonlinear frequency compression (NFC) and other frequency-lowering strategies is to increase the audibility of high-frequency sounds that are not otherwise audible with conventional hearing aid (HA) processing due to the degree of hearing loss, limited HA bandwidth, or a combination of both factors. The aim of the present study was to compare estimates of speech audibility processed by NFC with improvements in speech recognition for a group of children and adults with high-frequency hearing loss. DESIGN: Monosyllabic word recognition was measured in noise for 24 adults and 12 children with mild to severe sensorineural hearing loss. Stimuli were amplified based on each listener's audiogram with conventional processing (CP) with amplitude compression or with NFC and presented under headphones using a software-based HA simulator. A modification of the speech intelligibility index (SII) was used to estimate audibility of information in frequency-lowered bands. The mean improvement in SII was compared with the mean improvement in speech recognition. RESULTS: All but 2 listeners experienced improvements in speech recognition with NFC compared with CP, consistent with the small increase in audibility that was estimated using the modification of the SII. Children and adults had similar improvements in speech recognition with NFC. CONCLUSION: Word recognition with NFC was higher than CP for children and adults with mild to severe hearing loss. The average improvement in speech recognition with NFC (7%) was consistent with the modified SII, which indicated that listeners experienced an increase in audibility with NFC compared with CP. Further studies are necessary to determine whether changes in audibility with NFC are related to speech recognition with NFC for listeners with greater degrees of hearing loss, with a greater variety of compression settings, and using auditory training.

Effects of auditory training in individuals with high-frequency hearing loss.

OBJECTIVE: To determine the effects of a formal auditory training program on the behavioral, electrophysiological and subjective aspects of auditory function in individuals with bilateral high-frequency hearing loss. METHOD: A prospective study of seven individuals aged 46 to 57 years with symmetric, moderate high-frequency hearing loss ranging from 3 to 8 kHz was conducted. Evaluations of auditory processing (sound location, verbal and non-verbal sequential memory tests, the speech-in-noise test, the staggered spondaic word test, synthetic sentence identification with competitive ipsilateral and contralateral competitive messages, random gap detection and the standard duration test), auditory brainstem response and long-latency potentials and the administration of the Abbreviated Profile of Hearing Aid Benefit questionnaire were performed in a sound booth before and immediately after formal auditory training. RESULTS: All of the participants demonstrated abnormal pre-training long-latency characteristics (abnormal latency or absence of the P3 component) and these abnormal characteristics were maintained in six of the seven individuals at the post-training evaluation. No significant differences were found between ears in the quantitative analysis of auditory brainstem responses or long-latency potentials. However, the subjects demonstrated improvements on all behavioral tests. For the questionnaire, the difference on the background noise subscale achieved statistical significance. CONCLUSION: Auditory training in adults with high-frequency hearing loss led to improvements in figure-background hearing skills for verbal sounds, temporal ordination and resolution, and communication in noisy environments. Electrophysiological changes were also observed because, after the training, some long latency components that were absent pre-training were observed during the re-evaluation.