Quiet Thresholds Research Articles

Selective Inner Hair Cell Dysfunction in Chinchillas Impairs Hearing-in-Noise in the Absence of Outer Hair Cell Loss.

Poorer hearing in the presence of background noise is a significant problem for the hearing impaired. Ototoxic drugs, ageing, and noise exposure can damage the sensory hair cells of the inner ear that are essential for normal hearing sensitivity. The relationship between outer hair cell (OHC) loss and progressively poorer hearing sensitivity in quiet or in competing background noise is supported by a number of human and animal studies. In contrast, the effect of moderate inner hair cell (IHC) loss or dysfunction shows almost no impact on behavioral measures of hearing sensitivity in quiet, when OHCs remain intact, but the relationship between selective IHC loss and hearing in noise remains relatively unknown. Here, a moderately high dose of carboplatin (75mg/kg) that produced IHC loss in chinchillas ranging from 40 to 80% had little effect on thresholds in quiet. However, when tested in the presence of competing broadband (BBN) or narrowband noise (NBN), thresholds increased significantly. IHC loss >60% increased signal-to-noise ratios (SNRs) for tones (500-11,300Hz) in competing BBN by 5-10dB and broadened the masking function under NBN. These data suggest that IHC loss or dysfunction may play a significant role in listening in noise independent of OHC integrity and that these deficits may be present even when thresholds in quiet are within normal limits.

Measuring Temporal Resolution (Release of Masking) with a Hughson-Westlake Up-Down Instead of a Békèsy-Tracking Procedure.

A temporal resolution test in addition to the pure-tone audiogram may be of great clinical interest because of its relevance in speech perception and expected relevance in hearing aid fitting. Larsby and Arlinger developed an appropriate clinical test, but this test uses a Békèsy-tracking procedure for estimating masked thresholds in stationary and interrupted noise to assess release of masking (RoM) for temporal resolution. Generally the Hughson-Westlake up-down procedure is used in the clinic to measure the pure-tone thresholds in quiet. A uniform approach will facilitate clinical application and might be appropriate for RoM measurements as well. Because there is no golden standard for measuring the RoM in the clinic, we examine in the present study the Hughson-Westlake up-down procedure to measure the RoM and compare the results with the Békèsy-tracking procedure. The purpose of the current study was to examine the differences between a Békèsy-tracking procedure and the Hughson-Westlake up-down procedure for estimating masked thresholds in stationary and interrupted noise to assess RoM. RoM is assessed in eight normal-hearing (NH) and ten hearing-impaired (HI) listeners through both methods. Results from both methods are compared with each other and with predicted thresholds from a model. Wilcoxon signed-rank tests, paired t tests. Some differences between the two methods were found. We used a model to quantify the results of the two measurement procedures. The results of the Hughson-Westlake procedure were clearly better in agreement with the model than the results of the Békèsy-tracking procedure. Furthermore, the Békèsy-tracking procedure showed more spread in the results of the NH listeners than the Hughson-Westlake procedure. The Hughson-Westlake procedure seems to be an applicable alternative for measuring RoM for temporal resolution in the clinical audiological practice.

Evaluation of the effects of nonlinear frequency compression on speech recognition and sound quality for adults with mild to moderate hearing loss

Objective: While potentially improving audibility for listeners with considerable high frequency hearing loss, the effects of implementing nonlinear frequency compression (NFC) for listeners with moderate high frequency hearing loss are unclear. The purpose of this study was to investigate the effects of activating NFC for listeners who are not traditionally considered candidates for this technology. Design: Participants wore study hearing aids with NFC activated for a 3–4 week trial period. After the trial period, they were tested with NFC and with conventional processing on measures of consonant discrimination threshold in quiet, consonant recognition in quiet, sentence recognition in noise, and acceptableness of sound quality of speech and music. Study sample: Seventeen adult listeners with symmetrical, mild to moderate sensorineural hearing loss participated. Better ear, high frequency pure-tone averages (4, 6, and 8 kHz) were 60 dB HL or better. Results: Activating NFC resulted in lower (better) thresholds for discrimination of /s/, whose spectral center was 9 kHz. There were no other significant effects of NFC compared to conventional processing. Conclusion: These data suggest that the benefits, and detriments, of activating NFC may be limited for this population.

Computational modeling of individual differences in behavioral estimates of cochlear nonlinearities.

Temporal masking curves (TMCs) are often used to estimate cochlear compression in individuals with normal and impaired hearing. These estimates may yield a wide range of individual differences, even among subjects with similar quiet thresholds. This study used an auditory model to assess potential sources of variance in TMCs from 51 listeners in Poling et al. [J Assoc Res Otolaryngol, 13:91-108 (2012)]. These sources included threshold elevation, the contribution of outer and inner hair cell dysfunction to threshold elevation, compression of the off-frequency linear reference, and detection efficiency. Simulations suggest that detection efficiency is a primary factor contributing to individual differences in TMCs measured in normal-hearing subjects, while threshold elevation and the contribution of outer and inner hair cell dysfunction are primary factors in hearing-impaired subjects. Approximating the most compressive growth rate of the cochlear response from TMCs was achieved only in subjects with the highest detection efficiency. Simulations included off-frequency nonlinearity in basilar membrane and inner hair cell processing; however, this nonlinearity did not improve predictions, suggesting that other sources, such as the decay of masking and the strength of the medial olivocochlear reflex, may mimic off-frequency nonlinearity. Findings from this study suggest that sources of individual differences can play a strong role in behavioral estimates of compression, and these sources should be considered when using forward masking to study cochlear function in individual listeners or across groups of listeners.

The bonebridge as a transcutaneous bone conduction hearing system: preliminary surgical and audiological results in children and adolescents.

The Bonebridge (®) (BB, Med-El) is a newly designed transcutaneous active bone conductive implant with functional outcome similar to percutaneous bone-anchored hearing systems (BAHS). It is currently approved only for patients ≥18 years. Since the BB allows the skin to remain intact and therefore should be able to overcome some of the issues related to percutaneous BAHS including skin reactions, wound infection and implant extrusion, it would be especially attractive for use in children. We present a preliminary series of the first three cases of BB implantation in children/adolescents (10-16 years). Two subjects were affected by conductive hearing loss (CHL) and one subject by single-sided deafness (SSD). The surgical procedure with transmastoid approach was completed in all cases without complications. Both subjects with CHL showed an increase in speech perception thresholds in quiet from preoperative unaided to 6 months postoperatively with BB of 37 dB, respectively, of 12 dB. The adolescent with SSD attained -3.1 dB unaided vs. -5.6 dB with the BB in the "speech and noise from the front" presentation and +0.5 unaided vs. -5.0 dB with the BB in the "speech from the unilateral deaf side/noise from the normal hearing side" presentation using the adaptive Oldenburg Sentence Test. The results show a straightforward surgical procedure and satisfactory functional gain after BB implantation also in children/adolescents. BB implantation in patients ≤18 years is currently an "off-label use" so that detailed information about alternative treatment options, operation risks and the lack of approval for use in children is essential.

Effects of self-generated noise on estimates of detection threshold in quiet in school-age children and adults

Detection in quiet develops earlier in childhood for high than low frequencies. The present study tested the hypothesis that self-generated noise could play a role in this finding. When adults listen for sounds near threshold, they tend to engage in behaviors that reduce physiologic noise (e.g., quiet breathing), which is predominantly low frequency. Children may not suppress self-generated noise to the same extent as adults. This possibility was evaluated by measuring sound levels in the ear canal simultaneous with adaptive threshold estimation for 250-, 1000-, and 4000-Hz pure tones. Stimuli were delivered and recordings were made using a single foam insert. Listeners were children (4.3–16.0 yr) or adults. Consistent with previous data, the effect of child age was robust at 250 Hz, whereas thresholds of even the youngest listeners were nearly adult-like at 4000 Hz. The spectral shape of self-generated noise was generally similar across listener age groups, although the magnitude was higher in younger listeners. Trial-by-trial data were evaluated to assess the relationship between noise and the accuracy of listener responses: there was an association for younger listeners. These results provide preliminary evidence that self-generated noise may play a role in the prolonged development of low-frequency detection in quiet.

Prediction of IOI-HA scores using speech reception thresholds and speech discrimination scores in quiet.

Outcome measures can be used to improve the quality of the rehabilitation by identifying and understanding which variables influence the outcome. This information can be used to improve outcomes for clients. In clinical practice, pure-tone audiometry, speech reception thresholds (SRTs), and speech discrimination scores (SDSs) in quiet or in noise are common assessments made prior to hearing aid (HA) fittings. It is not known whether SRT and SDS in quiet relate to HA outcome measured with the International Outcome Inventory for Hearing Aids (IOI-HA). The aim of the present study was to investigate the relationship between pure-tone average (PTA), SRT, and SDS in quiet and IOI-HA in both first-time and experienced HA users. SRT and SDS were measured in a sample of HA users who also responded to the IOI-HA. Fifty-eight Danish-speaking adult HA users. The psychometric properties were evaluated and compared to previous studies using the IOI-HA. The associations and differences between the outcome scores and a number of descriptive variables (age, gender, fitted monaurally/binaurally with HA, first-time/experienced HA users, years of HA use, time since last HA fitting, best ear PTA, best ear SRT, or best ear SDS) were examined. A multiple forward stepwise regression analysis was conducted using scores on the separate IOI-HA items, the global score, and scores on the introspection and interaction subscales as dependent variables to examine whether the descriptive variables could predict these outcome measures. Scores on single IOI-HA items, the global score, and scores on the introspection (items 1, 2, 4, and 7) and interaction (items 3, 5, and 6) subscales closely resemble those previously reported. Multiple regression analysis showed that the best ear SDS predicts about 18-19% of the outcome on items 3 and 5 separately, and about 16% on the interaction subscale (sum of items 3, 5, and 6) CONCLUSIONS: The best ears SDS explains some of the variance displayed in the IOI-HA global score and the interaction subscale. The relation between SDS and IOI-HA suggests that a poor unaided SDS might in itself be a limiting factor for the HA rehabilitation efficacy and hence the IOI-HA outcome. The clinician could use this information to align the user's HA expectations to what is within possible reach.

Identification of Conductive Hearing Loss Using Air Conduction Tests Alone

The primary objective of this study was to determine whether a combination of automatically administered pure-tone audiometry and a tone-in-noise detection task, both delivered via an air conduction (AC) pathway, could reliably and validly predict the presence of a conductive component to the hearing loss. The authors hypothesized that performance on the battery of tests would vary according to hearing loss type. A secondary objective was to evaluate the reliability and validity of a novel automatic audiometry algorithm to assess its suitability for inclusion in the test battery. Participants underwent a series of hearing assessments that were conducted in a randomized order: manual pure-tone air conduction audiometry and bone conduction audiometry; automatic pure-tone air conduction audiometry; and an automatic tone-in-noise detection task. The automatic tests were each administered twice. The ability of the automatic test battery to: (a) predict the presence of an air-bone gap (ABG); and (b) accurately measure AC hearing thresholds was assessed against the results of manual audiometry. Test-retest conditions were compared to determine the reliability of each component of the automatic test battery. Data were collected on 120 ears from normal-hearing and conductive, sensorineural, and mixed hearing-loss subgroups. Performance differences between different types of hearing loss were observed. Ears with a conductive component (conductive and mixed ears) tended to have normal signal to noise ratios (SNR) despite impaired thresholds in quiet, while ears without a conductive component (normal and sensorineural ears) demonstrated, on average, an increasing relationship between their thresholds in quiet and their achieved SNR. Using the relationship between these two measures among ears with no conductive component as a benchmark, the likelihood that an ear has a conductive component can be estimated based on the deviation from this benchmark. The sensitivity and specificity of the test battery vary depending on the size of this deviation, but increase with increasing ABG size, with decreasing test frequency, and when results from multiple test frequencies are taken into account. The individual automatic tests comprising the battery were found to be reliable and valid, with strong, significant correlations between the test and retest results (r = 0.81 to 0.99; p < 0.0001) and between automatic and manual audiometry procedures (r = 0.98 to 0.99; p < 0.0001). The presence of an ABG can be predicted with a reasonably high degree of accuracy using AC tests alone. Applications of such a test battery include any clinical context in which bone conduction audiometry or specialized diagnostic equipment is unavailable or impractical. Examples of these include self-fitting hearing aids, whose efficacy relies on the ability of the device to automatically administer an in situ hearing test; self-administered adult hearing screenings in both clinical and home environments; large-scale industrial hearing conservation programs; and test environments in which ambient noise levels exceed the maximum permissible levels for unoccluded ears.

Spatial Separation Benefit for Unaided and Aided Listening

The benefit attributable to spatial separation of speech and noise was measured as a function of low-pass cutoff frequency with and without bilateral hearing aids. Fourteen younger and 10 older adults with normal hearing and 12 older adults with mild-to-moderate sloping high frequency hearing loss were included to assess the effects of age and hearing loss. Subjects with hearing loss were provided commercially available bilateral hearing aids. Consonant recognition was measured at 70 dB SPL in a background of speech-shaped noise at 66 dB SPL. Speech and noise were low-pass filtered at 1.7, 3.4, and 7.1 kHz. Nonsense syllables were always at 0° and noise was at either 0° or 90°. Speech and noise spectra for all conditions were digitally recorded using a probe microphone placed in each ear canal of each subject. Spectra and levels of speech, and quiet thresholds for narrowband noises, were used to calculate the Articulation Index and provide predictions of unaided and aided (hearing-impaired only) consonant recognition, spatial benefit, and hearing aid benefit for each condition. Subjective ratings of workload (NASA Task Load Index) were obtained for all unaided and aided measures of speech recognition. Consonant recognition in noise improved for all groups with speech and noise spatially separated and with the addition of high-frequency speech information. Scores were poorer overall for the older adults with hearing loss than for the other groups. For normal-hearing subjects, observed scores and spatial benefit were better than predicted. For hearing-impaired subjects, scores did not significantly improve with hearing aids, even with higher frequencies and spatial separation, and were poorer than predicted especially for aided listening. Similar to subjects with normal hearing, spatial benefit for hearing-impaired subjects was larger than predicted. Younger and older adults with normal hearing benefited from spatial separation of speech and noise sources to a greater extent than predicted based on simple audibility. Thus, no age-related deficits in the use of interaural difference cues were observed. Although hearing aid benefit was negligible, perceived listening effort was lower aided than unaided, especially with spatial separation. Articulation Index predictions revealed that speech audibility was generally restored with hearing aids across a wide bandwidth of speech, especially in the far ear. Thus, reduced audibility was not a primary factor in limited hearing aid benefit, suggesting that peripheral, central-auditory and/or cognitive changes may have played a role. In contrast, unaided and aided spatial benefit was better than predicted, and spatial benefit was slightly larger with hearing aids than without. Thus, these older adults with hearing loss using bilateral hearing aids were able to take advantage of binaural cues to improve consonant recognition in noise.

Evaluation of a New Powerful Bone-Anchored Hearing System: A Comparison Study

The recent introduction of digital hearing aid technology for bone-conduction devices employing percutaneous stimulation may be beneficial for patients with conductive and mixed hearing loss and single sided deafness. Performance of a recently released sound processor for bone-anchored implants, the Ponto Pro Power from Oticon Medical (bone-conduction device 2 [BCD2]), was compared with that of the Baha Intenso from Cochlear (bone-conduction device 1 [BCD1]). Direct comparison of the subject's own device (BCD1) with the new device (BCD2) was examined in a nonrandomized design. Subjects were initially tested with BCD1. BCD2 was tested after a 4 wk acclimatization period. Eighteen subjects with mixed hearing loss and with at least 4 mo experience with BCD1 completed the study. Mean air-conduction and bone-conduction thresholds averaged across the frequencies of 500, 1000, 2000, and 4000 Hz were 73.9 and 34.2 dB HL, respectively. Performance of the two devices was evaluated objectively by measuring aided free-field thresholds, speech perception in quiet, and speech perception in noise. A subjective evaluation was carried out with the Abbreviated Profile of Hearing Aid Benefit (APHAB) (Cox and Alexander, 1995) and the Speech, Spatial and Qualities of Hearing Scale (SSQ) questionnaire (Gatehouse and Noble, 2004). In addition, user experiences, user satisfaction, and device preference were obtained via proprietary questionnaires. Statistical significance was established with analysis-of-variance (ANOVA) and paired t-statistics with Bonferroni correction. Aided free-field thresholds and speech reception thresholds (SRTs) in quiet were not statistically significantly different for either device (p > 0.05). In contrast, SRTs in noise were 2.0 dB lower (p < 0.001) for BCD2 than for BCD1. APHAB questionnaire scores on all subscales provided statistically significantly greater benefit (p < 0.05) for BCD2 than for BCD1. Also, with the SSQ most items in the speech and sound quality domain were significantly more favorable (p < 0.05) for BCD2 than for BCD1. Finally, all subjects preferred BCD2 over BCD1 with 14 subjects reporting a strong preference and four subjects an average preference for the digital signal processing provided by BCD2 over previous technology provided by BCD1.

Auditory Training: Evidence for Neural Plasticity in Older Adults.

Improvements in digital amplification, cochlear implants, and other innovations have extended the potential for improving hearing function; yet, there remains a need for further hearing improvement in challenging listening situations, such as when trying to understand speech in noise or when listening to music. Here, we review evidence from animal and human models of plasticity in the brain's ability to process speech and other meaningful stimuli. We considered studies targeting populations of younger through older adults, emphasizing studies that have employed randomized controlled designs and have made connections between neural and behavioral changes. Overall results indicate that the brain remains malleable through older adulthood, provided that treatment algorithms have been modified to allow for changes in learning with age. Improvements in speech-in-noise perception and cognition function accompany neural changes in auditory processing. The training-related improvements noted across studies support the need to consider auditory training strategies in the management of individuals who express concerns about hearing in difficult listening situations. Given evidence from studies engaging the brain's reward centers, future research should consider how these centers can be naturally activated during training.

The Relationship between High-Frequency Pure-Tone Hearing Loss, Hearing in Noise Test (HINT) Thresholds, and the Articulation Index

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. This study investigates the relationship between pure-tone thresholds, the articulation index, and the ability to recognize speech in quiet and in noise. 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). 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. 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. 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. 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).

Individual and level-dependent differences in masking for adults with normal and impaired hearing

Simultaneous, on-frequency masking is commonly assumed to be linear with increasing noise intensity. However, some evidence suggests that, expressed in terms of signal-to-noise ratio changes with background level changes, masking slopes can vary from 0 dB/dB. These results and evidence from a large sample of subjects with normal and impaired hearing demonstrate level-dependent changes in masking, large individual differences in masking among subjects with similar thresholds in quiet, and significant correlations of masking slope with other estimates of auditory function measured in the same backgrounds.

Improving Hearing Aid Function in Noisy Situations

Improving Hearing Aid Function in Noisy Situations

Long-term effects of non-linear frequency compression for children with moderate hearing loss

Objective: To evaluate non-linear frequency compression (NLFC) as a means to improve speech recognition for children with moderate to moderately-severe hearing loss following a six-month acclimatization period. Design: Within subject design with repeated measures across test conditions. Study Sample: Fifteen children, ages 5 to 13 years, with moderate to moderately-severe high-frequency sensorineural hearing loss were fitted with Phonak Nios, micro-sized, BTE hearing aids and evaluated after two six-week intervals with and without NLFC and again after a six-month period of consecutive NLFC use. Results: Using repeated measures analyses, the six-month results were compared to data that was collected following six-week trials with and without NLFC hearing aids (). Improvements seen with NLFC in the initial study () were maintained or significantly increased in the present study. When compared to the six-week data, aided non-sense syllable speech recognition thresholds in quiet and speech recognition in noise were significantly better at the six-month interval. Conclusions: These results suggest that NLFC improves audibility for and recognition of high-frequency speech sounds for children with moderate to moderately-severe hearing loss. In many cases, improvements found with NLFC increased with a longer period of acclimatization to the technology.SumarioObjetivo: Evaluar la compresión no lineal de la frecuencia (NLFC) como un medio para mejorar el reconocimiento del lenguaje en niños con pérdidas auditivas moderadas a moderadamente severas, luego de un periodo de seis meses de aclimatación. Diseño: Es un diseño intra-sujeto con mediciones repetidas en todas las condiciones de la prueba Muestra del Estudio: Quince niños, edades de 5 a 13 años, con hipoacusia sensorineural moderada a moderadamente severa en altas frecuencias, fueron adaptados con auxiliares auditivos retroauriculares, de micro-tamaño, Phonak Nios, y evaluado luego de dos intervalos de seis semanas, con o sin NLFC y de nuevo, luego de un periodo de seis meses de uso consecutivo de NLFC. Resultados: Usando análisis de medidas repetidas, los resultados a seis meses se compararon con datos que fueron recogidos luego de periodos de seis semanas, con y sin auxiliares auditivos NLFC (Wolfe y col, en prensa). Las mejorías que se ven con NLFC en el estudio inicial (Wolfe y col, en prensa) se mantuvieron o fueron significativamente aumentadas en el presente estudio. Cuando se compararon con los datos de seis semanas, los umbrales no amplificados de reconocimiento del lenguaje para sílabas sin sentido en silencio y de reconocimiento del lenguaje en ruido, fueron significativamente mejores en el intervalo de seis meses. Conclusiones: Estos resultados sugieren que la NLFC mejora la audibilidad y el reconocimiento de sonidos lingüísticos de alta frecuencia para niños con hipoacusias moderadas a moderadamente severas. En muchos casos, la mejoría encontrada con NLFC aumentó con un periodo más largo de aclimatación a la tecnología.

Análise de resultados a partir de testes de sentenças e questionário de auto-avaliação

OBJETIVOS: investigar a melhora no desempenho e na restrição de participação de usuários de próteses auditivas, após um período de três meses, e verificar se houve correlação entre os resultados obtidos nestes dois aspectos. MÉTODOS: analisou-se 13 sujeitos, com perda auditiva do tipo neurossensorial de grau leve a moderadamente severo, com idades entre 28 e 60 anos. Realizou-se a pesquisa dos Limiares e Índices Percentuais de Reconhecimento de Sentenças no Silêncio e no Ruído (LRSS e LRSR, IPRSS e IPRSR), em campo livre, através do teste Listas de Sentenças em Português; e aplicou-se o questionário Hearing Handicap Inventory for Adults (HHIA). A primeira avaliação foi realizada antes da adaptação das próteses auditivas, sem o uso das mesmas, e a segunda, três meses após a adaptação, com o paciente fazendo uso das próteses auditivas. RESULTADOS: a an álise estatística evidenciou melhora significante, tanto em relação à restrição de participação (HHIA), quanto no desempenho das avaliações (LRSS, LRSR, IPRSS e IPRSR). Ao correlacionar a melhora na restrição de participação (HHIA), com a melhora do desempenho nos demais procedimentos, houve correlação significante apenas entre a melhora no HHIA e a melhora no LRSR. CONCLUSÃO: os usuários avaliados apresentaram sensação de restrição da participação diminuída, e melhora significante no desempenho em situações de reconhecimento de fala, tanto no silêncio quanto no ruído. Houve correlação entre a melhora nas respostas no HHIA e o LRSR, devido ao fato de que as maiores queixas em indivíduos com perda auditiva neurossensorial estarem relacionadas à presença de ruído competitivo.

A satisfação e o desempenho de usuários de próteses auditivas atendidos em um programa de atenção à saúde auditiva

OBJETIVO: avaliar o desempenho e a satisfação com o uso das próteses auditivas nos pacientes atendidos no convênio APAC-UFSM, após um ano de adaptação. MÉTODOS: analisou-se 49 sujeitos, com perda auditiva do tipo neurossensorial ou mista, de grau leve a severo na melhor orelha, divididos em adultos e idosos. Realizou-se a pesquisa dos Limiares e Índices Percentuais de Reconhecimento de Sentenças no Silêncio e no Ruído, em campo livre, por meio do teste Listas de Sentenças em Português; e aplicou-se o questionário de satisfação, International Outcome Inventory for Hearing Aids. Realizaram-se os testes na mesma sessão, em dois momentos distintos, sendo o primeiro, sem o uso das próteses auditivas e o segundo, usando as mesmas. RESULTADOS: houve diferença significante no desempenho dos indivíduos em ambos os grupos, no procedimento realizado no silêncio. Apesar de o desempenho com próteses auditivas não ter apresentado melhora significante no ruído, os pacientes apresentaram respostas satisfatórias no questionário. Na comparação entre os grupos, não se observou diferença significante quanto ao desempenho e satisfação. CONCLUSÃO: a melhora significante do desempenho no silêncio vai ao encontro do relato dos pacientes. O questionário evidenciou que a maioria referiu fazer uso efetivo das próteses auditivas e considerou ter um benefício muito satisfatório. Apesar de uma parcela significativa referir moderada ou bastante dificuldade residual, a maioria considerou que o uso das próteses auditivas vale muito ou bastante a pena.

Speech Perception in Quiet and Noise Using the Hearing in Noise Test and the Japanese Hearing in Noise Test by Japanese Listeners

The aim of this study was to evaluate the first-language (L1) and second-language (L2) perception abilities in quiet and noise of native Japanese listeners who acquired English late in life and lived in the United States. The study addressed two primary questions: (1) whether native Japanese listeners who developed some fluency in English showed poorer English speech perception ability in quiet and noise than native English listeners, and (2) whether native Japanese listeners living in an English-speaking environment demonstrated poorer speech perception ability in Japanese than native Japanese listeners who reside in Japan and rarely use a second language. Ten native Japanese adults who had excellent English word recognition ability in quiet were evaluated using the English and Japanese versions of the Hearing in Noise Test (HINT). In addition, 10 native English adults were evaluated using the English version of the HINT. All Japanese participants started learning English between the ages of 12 and 13 yrs while at school in Japan and had lived in the United States more than 4 yrs. An adaptive procedure was used to measure English and Japanese speech recognition thresholds (SRTs) in quiet and signal-to-noise ratios (SNRs) at which SRTs were obtained in noise conditions. In addition, a fixed-level procedure was used to obtain percent correct recognition scores at five different SNRs. Both HINT sentence stimuli and noise were presented at a simulated 0° azimuth under headphones. The Japanese group had significantly poorer English speech perception ability than the native English group in all the test conditions under both the adaptive and fixed-level procedures. The psychometric function for the Japanese listeners was shifted by approximately 3 to 4 dB SNR from that of the native English listeners. Japanese speech recognition ability by the Japanese group was not significantly different from that of native Japanese speakers who live in Japan. The Japanese participants who had excellent English word recognition ability in quiet listening conditions failed to reach native-like English speech perception when presented with sentences in quiet conditions. In addition, all 10 Japanese listeners examined in this study had HINT SNRs (i.e., SNRs at which SRTs were obtained in noise conditions) outside the normal range. However, the possible deterioration of L1 speech perception after living in the L2 environment for an extended period of time was not observed among the Japanese, late L2 learners in this study. The implication of this study for clinical settings is that it is important to use L1 sentence materials in both quiet and noise to examine the speech recognition performance of L2 (English) users who had acquired L2 after puberty.

Fine Structure Processing improves speech perception as well as objective and subjective benefits in pediatric MED-EL COMBI 40+ users

Objectives Presently, there are only few studies examining the benefits of fine structure information in coding strategies. Against this background, this study aims to assess the objective and subjective performance of children experienced with the C40+ cochlear implant using the CIS+ coding strategy who were upgraded to the OPUS 2 processor using FSP and HDCIS. Methods In this prospective study, 60 children with more than 3.5 years of experience with the C40+ cochlear implant were upgraded to the OPUS 2 processor and fit and tested with HDCIS (Interval I). After 3 months of experience with HDCIS, they were fit with the FSP coding strategy (Interval II) and tested with all strategies (FSP, HDCIS, CIS+). After an additional 3–4 months, they were assessed on all three strategies and asked to choose their take-home strategy (Interval III). The children were tested using the Adaptive Auditory Speech Test which measures speech reception threshold (SRT) in quiet and noise at each test interval. The children were also asked to rate on a Visual Analogue Scale their satisfaction and coding strategy preference when listening to speech and a pop song. However, since not all tests could be performed at one single visit, some children were not able complete all tests at all intervals. Results At the study endpoint, speech in quiet showed a significant difference in SRT of 1.0 dB between FSP and HDCIS, with FSP performing better. FSP proved a better strategy compared with CIS+, showing lower SRT results of 5.2 dB. Speech in noise tests showed FSP to be significantly better than CIS+ by 0.7 dB, and HDCIS to be significantly better than CIS+ by 0.8 dB. Both satisfaction and coding strategy preference ratings also revealed that FSP and HDCIS strategies were better than CIS+ strategy when listening to speech and music. FSP was better than HDCIS when listening to speech. Conclusions This study demonstrates that long-term pediatric users of the COMBI 40+ are able to upgrade to a newer processor and coding strategy without compromising their listening performance and even improving their performance with FSP after a short time of experience.

Effects of background noise level on behavioral estimates of basilar-membrane compression.

Hearing-impaired (HI) listeners often show poorer performance on psychoacoustic tasks than do normal-hearing (NH) listeners. Although some such deficits may reflect changes in suprathreshold sound processing, others may be due to stimulus audibility and the elevated absolute thresholds associated with hearing loss. Masking noise can be used to raise the thresholds of NH to equal the thresholds in quiet of HI listeners. However, such noise may have other effects, including changing peripheral response characteristics, such as the compressive input-output function of the basilar membrane in the normal cochlea. This study estimated compression behaviorally across a range of background noise levels in NH listeners at a 4 kHz signal frequency, using a growth of forward masking paradigm. For signals 5 dB or more above threshold in noise, no significant effect of broadband noise level was found on estimates of compression. This finding suggests that broadband noise does not significantly alter the compressive response of the basilar membrane to sounds that are presented well above their threshold in the noise. Similarities between the performance of HI listeners and NH listeners in threshold-equalizing noise are therefore unlikely to be due to a linearization of basilar-membrane responses to suprathreshold stimuli in the NH listeners.