Over 360 million people worldwide suffer from disabling hearing loss. Most of them can be treated with aids. Unfortunately, performance aids and the benefit obtained using vary widely across users. Here, we investigate reasons for such variability. Sixty-eight hearing-aid users or candidates were fitted bilaterally nonlinear standard procedures. Treatment outcome was assessed by measuring aided speech intelligibility in a time-reversed two-talker background self-reported improvement ability....

The aim of this study was to assess the relative importance cochlear mechanical dysfunction, temporal processing deficits, and age on ability hearing-impaired listeners understand speech in noisy backgrounds. Sixty-eight took part study. They were provided with linear, frequency-specific amplification compensate for their audiometric losses, intelligibility assessed speech-shaped noise (SSN) a time-reversed two-talker masker (R2TM). Behavioral estimates gain loss residual compression...

Older people often show auditory temporal processing deficits and speech-in-noise intelligibility difficulties even when their audiogram is clinically normal. The causes of such problems remain unclear. Some studies have suggested that for with normal audiograms, age-related hearing impairments may be due to a cognitive decline, while others they caused by cochlear synaptopathy. Here, we explore an alternative hypothesis, namely are associated decreased inhibition. For human adults (N = 30)...

Central gain compensation for reduced auditory nerve output has been hypothesized as a mechanism tinnitus with normal audiogram. Here, we investigate if occurs aging. For 94 people (aged 12–68 years, 64 women, 7 tinnitus) or close-to-normal audiograms, the amplitude of wave I brainstem response decreased increasing age but was not correlated V after accounting age-related subclinical hearing loss and cochlear damage, result indicative compensation. The correlations between I/III III/V ratios...

Identifying the multiple contributors to audiometric loss of a hearing impaired listener at particular frequency is becoming gradually more useful as new treatments are developed. Here, we infer contribution inner (IHC) and outer hair cell (OHC) dysfunction total in sample 68 aid candidates with mild-to-severe sensorineural loss, for test frequencies 0.5, 1, 2, 4, 6 kHz. It was assumed that (HL_TOTAL) each due combination cochlear gain or OHC (HL_OHC), inefficient IHC processes (HL_IHC), all...

The aim was to investigate the correlation between compression exponent, threshold, and cochlear gain for normal-hearing subjects as inferred from temporal masking curves (TMCs) distortion-product otoacoustic emission (DPOAEs) input–output (I/O) curves. Care given reduce influence of DPOAE fine structure on I/O A high exponent estimates obtained with two methods found at 4kHz but not 0.5 1kHz. One reason is that show plateaus or notches result in unexpectedly estimates. Moderately threshold...

The present study aimed at characterizing the suppressing effect of contralateral medial olivocochlear (MOC) efferents on human auditory sensitivity and mechanical cochlear responses sound levels near behavioral thresholds. Absolute thresholds for pure tones 500 4000 Hz with durations between 10 to ms were measured in presence absence a broadband noise. intensity noise was fixed 60 dB SPL evoke MOC reflex without evoking middle-ear muscle reflex. In agreement previously reported findings,...

Previous studies have shown a high within-subject correspondence between distortion product otoacoustic emission (DPOAE) input/output (I/O) curves and behaviorally inferred basilar membrane (BM) I/O for frequencies above approximately 2 kHz. For lower frequencies, DPOAE contained notches plateaus that did not counterpart in corresponding behavioral curves. It was hypothesized this might improve by using individualized optimal primary levels. Here, data from previous are re-analyzed to test...

We report a theoretical study aimed at investigating the impact of cochlear synapse loss (synaptopathy) on encoding envelope (ENV) and temporal fine structure (TFS) sounds by population auditory nerve fibers. A computational model was used to simulate auditory-nerve spike trains evoked sinusoidally amplitude-modulated (AM) tones 10 Hz with various carrier frequencies levels. The included 16 channels characteristic (CFs) from 250 8 kHz. Each channel innervated 3, 4 fibers low (LSR), medium...

The roles of the medial olivocochlear reflex (MOCR) in human hearing have been widely investigated but remain controversial. We reason that this may be because effects MOCR activation on cochlear mechanical responses can assessed only indirectly healthy humans, and different methods used to assess those possibly yield and/or unreliable estimates. One aim study was investigate correlation between three often employed strength by contralateral acoustic stimulation (CAS). measured tone...

Cochlear hearing loss is one of the most common forms disability. It frequently relates to selective or combined dysfunction inner (IHCs) and outer hair cells (OHCs). Current clinical methods do not allow an accurate estimation degree each cell type, yet such could be highly informative for optimizing aid fitting. Here, it proposed that IHC OHC may estimated from DPOAE input/output curves. argued controversial aspects interpretation these curves elucidated by comparing with corresponding...

We compared sound quality and performance for a conventional cochlear-implant (CI) audio processing strategy based on short-time fast-Fourier transform (Crystalis) an experimental spectral feature extraction (SFE). In the latter, more salient features (acoustic events) were extracted mapped into CI stimulation electrodes. hypothesized that (1) SFE would be superior to Crystalis because it can encode acoustic without constraints imposed by bin width, (2) potential benefit of greater users who...

AbstractAbstractThe aim of this study was to provide statistical information on otoacoustic emission (OAE) measurements in new-born infants, which could be useful the interpretation results and add some clinical parameters that might used for future objective automatic response evaluations. Transient evoked OAEs (TEOAEs) using maximum length sequences (MLS) were recorded 129 full-term infants between 48 72 hours age. The use MLS enabled stimulus rates up 2000/sec utilized. analysis comprised...

The temporal masking curve (TMC) method is a behavioral technique for inferring human cochlear compression. relies on the assumptions that in absence of compression, forward-masking recovery independent masker level and probe frequency. present study aimed at testing validity these assumptions. Masking was investigated eight listeners with sensorineural hearing loss carefully selected to have absent or nearly distortion product otoacoustic emissions. It assumed basilar membrane responses are...

Computational models are useful tools to investigate scientific questions that would be complicated address using an experimental approach. In the context of cochlear-implants (CIs), being able simulate neural activity evoked by these devices could help in understanding their limitations provide natural hearing. Here, we present a computational modelling framework quantify transmission information from sound spikes auditory nerve CI user. The includes model electrical current waveform sensed...

A system for recording Transient Evoked Otoacoustic Emissions (TEOAE) neonatal screening, utilizing Maximum Length Sequences (MLS) the generation of stimulus signals, is described. The main advantage its ability to obtain responses within a very short period time, compared conventional OAE systems. actual time MLS reduced by factor between 10 and 20 comparable signal-to-noise ratios. Stimulus levels range from 50 90 dB peak equivalent SPL available rates are 31, 62, 125, 250, 500, 1000...

The aim was to investigate the correlation between estimates of compression ratio, threshold, and cochlear gain for normal-hearing subjects inferred from temporal masking curves (TMC) distortion-product otoacoustic emission (DPOAEs) input-output (I/O) curves. Special care given reduce influence DPOAE fine structure on I/O Data were collected 10 places with characteristic frequencies (CFs) 0.5, 1, 2, 4 kHz. Except at kHz, little found ratio obtained two methods. One reason is that show...

Exposure to brief, intense sound can produce profound changes in the auditory system, from internal structure of inner hair cells reduced synaptic connections between nerves and cells. Moreover, noisy environments also lead alterations nerve or processing midbrain, all without affecting hearing thresholds. This so-called hidden loss (HHL) has been shown tinnitus patients posited account for difficulties environments. However, much neuronal research thus far investigated how HHL affects...