Pure-tone Thresholds Research Articles

Predicting Postoperative Speech Perception and Audiometric Thresholds Using Intracochlear Electrocochleography in Cochlear Implant Recipients.

Electrocochleography (ECochG) appears to offer the most accurate prediction of post-cochlear implant hearing outcomes. This may be related to its capacity to interrogate the health of underlying cochlear tissue. The four major components of ECochG (cochlear microphonic [CM], summating potential [SP], compound action potential [CAP], and auditory nerve neurophonic [ANN]) are generated by different cochlear tissue components. Analyzing characteristics of these components can reveal the state of hair and neural cell in a cochlea. There is limited evidence on the characteristics of intracochlear (IC) ECochG recordings measured across the array postinsertion but compared with extracochlear recordings has better signal to noise ratio and spatial specificity. The present study aimed to examine the relationship between ECochG components recorded from an IC approach and postoperative speech perception or audiometric thresholds. In 113 human subjects, responses to 500 Hz tone bursts were recorded at 11 IC electrodes across a 22-electrode cochlear implant array immediately following insertion. Responses to condensation and rarefaction stimuli were then subtracted from one another to emphasize the CM and added to one another to emphasize the SP, ANN, and CAP. Maximum amplitudes and extracochlear electrode locations were recorded for each of these ECochG components. These were added stepwise to a multi-factor generalized additive model to develop a best-fit model predictive model for pure-tone audiometric thresholds (PTA) and speech perception scores (speech recognition threshold [SRT] and consonant-vowel-consonant phoneme [CVC-P]) at 3- and 12-month postoperative timepoints. This best-fit model was tested against a generalized additive model using clinical factors alone (preoperative score, age, and gender) as a null model proxy. ECochG-factor models were superior to clinical factor models in predicting postoperative PTA, CVC-P, and SRT outcomes at both timepoints. Clinical factor models explained a moderate amount of PTA variance ( r2 = 45.9% at 3-month, 31.8% at 12-month, both p < 0.001) and smaller variances of CVC-P and SRT ( r2 range = 6 to 13.7%, p = 0.008 to 0.113). Age was not a significant predictive factor. ECochG models explained more variance at the 12-month timepoint ( r2 for PTA = 52.9%, CVC-P = 39.6%, SRT = 36.4%) compared with the 3-month one timepoint ( r2 for PTA = 49.4%, CVC-P = 26.5%, SRT = 22.3%). The ECochG model was based on three factors: maximum SP deflection amplitude, and electrode position of CM and SP peaks. Adding neural (ANN and/or CAP) factors to the model did not improve variance explanation. Large negative SP deflection was associated with poorer outcomes and a large positive SP deflection with better postoperative outcomes. Mid-array peaks of SP and CM were both associated with poorer outcomes. Postinsertion IC-ECochG recordings across the array can explain a moderate amount of postoperative speech perception and audiometric thresholds. Maximum SP deflection and its location across the array appear to have a significant predictive value which may reflect the underlying state of cochlear health.

The Not-So-Slight Perceptual Consequences of Slight Hearing Loss in School-Age Children: A Scoping Review.

This study aimed to conduct a scoping review of research exploring the effects of slight hearing loss on auditory and speech perception in children. A comprehensive search conducted in August 2023 identified a total of 402 potential articles sourced from eight prominent bibliographic databases. These articles were subjected to rigorous evaluation for inclusion criteria, specifically focusing on their reporting of speech or auditory perception using psychoacoustic tasks. The selected studies exclusively examined school-age children, encompassing those between 5 and 18 years of age. Following rigorous evaluation, 10 articles meeting these criteria were selected for inclusion in the review. The analysis of included articles consistently shows that even slight hearing loss in school-age children significantly affects their speech and auditory perception. Notably, most of the included articles highlighted a common trend, demonstrating that perceptual deficits originating due to slight hearing loss in children are particularly observable under challenging experimental conditions and/or in cognitively demanding listening tasks. Recent evidence further underscores that the negative impacts of slight hearing loss in school-age children cannot be solely predicted by their pure-tone thresholds alone. However, there is limited evidence concerning the effect of slight hearing loss on the segregation of competing speech, which may be a better representation of listening in the classroom. This scoping review discusses the perceptual consequences of slight hearing loss in school-age children and provides insights into an array of methodological issues associated with studying perceptual skills in school-age children with slight hearing losses, offering guidance for future research endeavors.

Agreement between audiometric hearing loss and self-reported hearing difficulty on the Revised Hearing Handicap Inventory differs by demographic factors

BackgroundNew standardised measures of self-reported hearing difficulty can be validated against audiometric hearing loss. This study reports the influence of demographic factors (age, sex, race and socioeconomic position (SEP)) on...

Effects of hearing acuity on psychophysiological responses to effortful speech perception

In recent studies, psychophysiological measures have been used as markers of listening effort, but there is limited research on the effect of hearing loss on such measures. The aim of the current study was to investigate the effect of hearing acuity on physiological responses and subjective measures acquired during different levels of listening demand, and to investigate the relationship between these measures. A total of 125 participants (37 males and 88 females, age range 37–72 years, pure-tone average hearing thresholds at the best ear between -5.0 to 68.8 dB HL and asymmetry between ears between 0.0 and 87.5 dB) completed a listening task. A speech reception threshold (SRT) test was used with target sentences spoken by a female voice masked by male speech. Listening demand was manipulated using three levels of intelligibility: 20 % correct speech recognition, 50 %, and 80 % (IL20 %/IL50 %/IL80 %, respectively). During the task, peak pupil dilation (PPD), heart rate (HR), pre-ejection period (PEP), respiratory sinus arrhythmia (RSA), and skin conductance level (SCL) were measured. For each condition, subjective ratings of effort, performance, difficulty, and tendency to give up were also collected. Linear mixed effects models tested the effect of intelligibility level, hearing acuity, hearing asymmetry, and tinnitus complaints on the physiological reactivity (compared to baseline) and subjective measures. PPD and PEP reactivity showed a non-monotonic relationship with intelligibility level, but no such effects were found for HR, RSA, or SCL reactivity. Participants with worse hearing acuity had lower PPD at all intelligibility levels and showed lower PEP baseline levels. Additionally, PPD and SCL reactivity were lower for participants who reported suffering from tinnitus complaints. For IL80 %, but not IL50 % or IL20 %, participants with worse hearing acuity rated their listening effort to be relatively high compared to participants with better hearing. The reactivity of the different physiological measures were not or only weakly correlated with each other. Together, the results suggest that hearing acuity may be associated with altered sympathetic nervous system (re)activity. Research using psychophysiological measures as markers of listening effort to study the effect of hearing acuity on such measures are best served by the use of the PPD and PEP.

Neural Adaptation at Stimulus Onset and Speed of Neural Processing as Critical Contributors to Speech Comprehension Independent of Hearing Threshold or Age.

Background: It is assumed that speech comprehension deficits in background noise are caused by age-related or acquired hearing loss. Methods: We examined young, middle-aged, and older individuals with and without hearing threshold loss using pure-tone (PT) audiometry, short-pulsed distortion-product otoacoustic emissions (pDPOAEs), auditory brainstem responses (ABRs), auditory steady-state responses (ASSRs), speech comprehension (OLSA), and syllable discrimination in quiet and noise. Results: A noticeable decline of hearing sensitivity in extended high-frequency regions and its influence on low-frequency-induced ABRs was striking. When testing for differences in OLSA thresholds normalized for PT thresholds (PTTs), marked differences in speech comprehension ability exist not only in noise, but also in quiet, and they exist throughout the whole age range investigated. Listeners with poor speech comprehension in quiet exhibited a relatively lower pDPOAE and, thus, cochlear amplifier performance independent of PTT, smaller and delayed ABRs, and lower performance in vowel-phoneme discrimination below phase-locking limits (/o/-/u/). When OLSA was tested in noise, listeners with poor speech comprehension independent of PTT had larger pDPOAEs and, thus, cochlear amplifier performance, larger ASSR amplitudes, and higher uncomfortable loudness levels, all linked with lower performance of vowel-phoneme discrimination above the phase-locking limit (/i/-/y/). Conslusions: This study indicates that listening in noise in humans has a sizable disadvantage in envelope coding when basilar-membrane compression is compromised. Clearly, and in contrast to previous assumptions, both good and poor speech comprehension can exist independently of differences in PTTs and age, a phenomenon that urgently requires improved techniques to diagnose sound processing at stimulus onset in the clinical routine.

Serial monitoring of the audiogram in hearing conservation using Gaussian processes

Most hearing conservation programs repeatedly monitor a subject's pure tone thresholds before, during, and after exposure to audiopathic agents. Changes to the audiogram that meet significant shift criteria such as ASHA, CTCAE, and so forth are considered evidence of audiopathic injury. Despite a wide variety of definitions for significant change, all current serial monitoring methods are biased due to regression to the mean and are prone to inconclusive results. These problems diminish the diagnostic accuracy and utility of serial monitoring. Here we propose adopting Gaussian processes to address these issues in a manner that maximizes time efficiency and can be administered using portable equipment at the point of care.

Relationship Between Hypertension and Hearing Loss: Analysis of the Related Factors.

The impact of hypertension extends to hearing loss, aging, and mental Health. The purpose of this study was to investigate the characteristics of hearing loss and hearing thresholds at different frequencies in individuals with hypertension. Through a comprehensive analysis, in the present study, it aimed to uncover the contributing factors that underlie hearing loss in this patient cohort, shedding light on the complex relationship between hypertension and auditory impairment. This was a single-center population-based observational study, and clinical, biological, and hospital data were collected from the inpatient ward. In the present study, 517 patients (1034 ears) with or without hypertension were included, and the proportion of patients with hearing loss, mean pure-tone average hearing threshold, low-frequency pure-tone average hearing threshold (LFPTA), medium-frequency pure-tone average hearing threshold (MFPTA) and high-frequency pure-tone average hearing threshold (HFPTA) were evaluated. Risk factors related to hearing loss and hearing threshold were also estimated at different frequencies. The proportion of patients with hearing loss was higher in the hypertensive group than in the nonhypertensive group (P<0.05). After including risk factors for cardiovascular disease that can have an impact on the parameters of hearing and ambulatory blood pressure in the regression model, factors related to hearing loss included the albumin-to-creatinine ratio (ACR) and the standard deviation of the 24-hour systolic blood pressure (24h-SSD). ACR, 24h-SSD, and day systolic blood pressure (Day SBP) were associated with the mean pure-tone average hearing threshold, LFPTA, MFPTA, and HFPTA. The area under the receiver operating characteristic curve of ACR + 24h-SSD for hearing loss was 0.873, with a sensitivity of 86.73%, specificity of 90.52%, and a 95% confidence interval of 0.821-0.914. Hypertension is correlated with hearing loss, and the combination of ACR and 24h-SSD demonstrates an improved predictive capacity for hearing loss in hypertensive patients.

Prediction of pure tone thresholds using the speech reception threshold and age in elderly individuals with hearing loss.

Early detection and effective management of hearing loss constitute the key to improving the quality of life of individuals with hearing loss. However, in standardized pure tone audiometry, it is sometimes difficult for elderly patients to understand and follow all instructions. Audiologists also require time, expertise, and patience to ensure that an elderly can identify the faintest levels of stimuli during a hearing test. Therefore, this study aimed to devise and validate a formula to predict the pure tone threshold at each frequency across 0.5-4kHz (PTTs) using speech reception threshold. The 1226 audiograms of hearing-impaired individuals aged 60-90 years were reviewed. The random sample function randomly assigned 613 participants to the training and testing sets each. A linear model was created to predict the PTT value at each frequency based on variables significant at all frequencies across 0.5-4kHz. The adjusted-R2 value was considered to indicate the performance of the predictive model. Pearson's correlation coefficient was used to describe the relationship between the actual and predicted PTT at 0.5, 1, 2, and 4kHz among the testing set to measure the performance of the proposed model. The predictive model was devised using variables based on the speech recognition threshold (SRT) after adjusting with age in the training set. The overall prediction accuracy demonstrated a higher adjusted-R2 ranging from 0.74 to 0.89 at frequencies of 0.5, 1, and 2kHz, whereas a low percentage of explained variance was observed at 4kHz (adjusted-R2 = 0.41). This predictive model can serve as an adjunctive clinical tool for guiding determination of the PTTs. Moreover, the predicted PTTs can be applied in the hearing aid programming software to set appropriate hearing aid gain using standard prescriptive formulas.

Hearing health survey of the population in Bangkok

In this cross-sectional random survey among Thai adults living in Bangkok, we aimed to identify the prevalence of hearing problems and examine their relationship with individual factors. We administered a self-report questionnaire and performed pure-tone air conduction threshold audiometry. A total of 2463 participants (1728 female individuals) aged 15–96 years were included. The hearing loss prevalence was 53.02% and increased with age. The prevalence of a moderate or greater degree of hearing impairment was 2.8%. Participants aged 65 years and over had 8.56 and 6.79 times greater hearing loss and hearing impairment than younger participants, respectively. Male participants were twice as likely to have hearing loss and hearing impairment as female individuals. Participants with higher education levels showed less likelihood of having hearing loss and hearing impairment than those with no or a primary school education. Participants who ever worked under conditions with loud noise for > 8 h per day had 1.56 times greater hearing loss than those without such exposure. An inconsistent correlation was found between hearing loss, hearing impairment and noncommunicable diseases (diabetes, hypertension, and obesity). Although most participants had mild hearing loss, appropriate care and monitoring are necessary to prevent further loss in such individuals. The questionnaire-based survey found only people with hearing problems that affect daily communication.

Assessing the accuracy and reliability of application-based audiometry for hearing evaluation

Pure-tone audiometry (PTA) is the gold standard for assessing hearing loss. However, traditional PTA tests require specialized equipment, trained personnel, and a soundproof environment. Recently, smartphone-based PTA tests have been developed as an alternative method for hearing assessment. The aim of this study was to validate the accuracy and reliability of a smartphone application-based audiometry test. This study was conducted to assess the performance of application-based audiometry from November 2021 to January 2022. Pure-tone thresholds were measured using a smartphone application-based PTA test and compared with results obtained using a traditional audiometer in a sound-treated booth. The smartphone application used in this study was the "Care4Ear (Care4ear, version 1.0.6, MIJ Co., Ltd.)". Hearing thresholds less than 35 dB HL were classified as group A, 35-64 dB HL as group B, and 65 dB HL or greater as group C for the classification of hearing levels. We evaluated the accuracy of smartphone audiometry for each group and compared the results of frequency-specific hearing tests. Additionally, we examined the results of smartphone audiometry in individuals (n = 27) with asymmetric hearing loss. Seventy subjects completed both conventional audiometry and smartphone application-based hearing tests. Among the ears assessed, 55.7% were classified as group A, while 25.7% and 18.6% were classified as group B and group C, respectively. The average hearing threshold obtained from conventional pure-tone audiometry was 37.7 ± 25.2 dB HL, whereas the application-based hearing test yielded thresholds of 21.0 ± 23.0 dB HL. A significant correlation (r = 0.69, p < 0.01) was found between the average hearing thresholds obtained from the application-based and conventional pure-tone audiometry tests. The application-based test achieved a 97.4% hit rate for classifying hearing thresholds as class A, but lower rates of 22.2% for class B and 38.5% for class C. Notably, a discrepancy was observed between the hearing threshold measured by the application and the conventional audiometry for the worse ear with asymmetric hearing. The smartphone-based audiometry is a feasible method for hearing evaluation especially in persons with normal hearing. In cases of hearing loss or asymmetric hearing loss, the results of the application-based audiometry may be inaccurate, limiting its diagnostic utility.

Standard and Extend High-Frequency Audiometry in Sudden Sensorineural Hearing Loss: Impacts on Tinnitus and Mental Health.

To analyze the results of auditory assessment in standard (SA) and extended high-frequency (EHF) audiometry, associating the findings with sudden tinnitus and mental health of patients with unilateral sudden sensorineural hearing loss (SSNHL). Prospective, cohort study. Outpatient otology clinic in a tertiary care hospital. Patients experiencing unilateral SSNHL were evaluated with pure-tone audiometry performed at frequencies of 250 to16,000 Hz, tinnitus pitch and loudness matching tests, Tinnitus Handicap Inventory (THI), Analog and Visual Scale (AVS) for bothersome tinnitus, and the Hospital Anxiety and Depression Scale (HADS). Eighteen patients with unilateral SSNHL were assessed. After starting treatment, there was a significant improvement in the SA (71.1 dB to 50 dB; p < 0.001*) and EHF audiometry (64.5 dB to 54.4 dB; p < 0.001*) thresholds at 15 days, and this persisted at 30 days of follow-up. Significant improvements were seen for tinnitus in loudness, VAS, and THI and for mental health in the realms of anxiety and depression by HADS. Despite improvements in SA, persistent EHF hearing loss was accompanied by persistent tinnitus, but it was of diminished loudness. Despite improvement in pure-tone thresholds by SA, a subset of unilateral SSNHL patients did not experience hearing recovery in EHF thresholds and reported persistent tinnitus. We postulate that their diminished anxiety and better mental health may be related to both hearing improvement in standard audiometry and reduction in tinnitus loudness. This pilot prospective study investigates the utility of performing EHF audiometry to better understand outcomes in patients with SSNHL.

Functional outcomes and caloric response changes after endolymphatic sac decompression

ObjectiveTo evaluate caloric response changes after endolymphatic sac decompression (ESD), together with hearing outcomes and the functional benefit of the operation. MethodsA retrospective chart review of subjects who underwent endolymphatic sac decompression at a tertiary referral centre was performed. Data on audiological results, caloric testing, and functional level scale of the patients were analysed. ResultsTwenty-eight patients who met our criteria were eligible for enrolment in the study. The average follow-up after surgery was 25 months (range, 13–41). Postoperative pure-tone threshold averages and reduced vestibular response values (RVR) were not significantly altered by ESD; whereas, functional level scores improved significantly. ConclusionEndolymphatic sac decompression is a surgical procedure that preserves hearing and vestibular function, and improves the daily functional level of patients with Ménière's disease. ESD can be preferred both in bilateral and unilateral disease because it does not alter vestibular function and preserves hearing.

Experiencia clínica con el implante coclear Nurotron™ en una población postlingual hispanohablante: seguridad clínica y resultados audiólogicos

Objectiveto assess clinical safety and postoperative audiological outcomes in postlingual deafness Spanish speaking patients, who underwent surgery with Nurotron™ cochlear implant. Material and MethodsRetrospective descriptive case series study. We performed follow-up of complications and audiological measurements before and after cochlear implantation. Patients with bilateral severe to profound sensorineural hearing loss or patients with unilateral deafness with/without tinnitus were included. Repeated-measures within-subjects for assess pure tone thresholds and speech performance (bilingual test) with a detailed monitoring to establish security or adverse effects were performed. Analysis of variance tests, repetitive measures, were used for statistical analysis. Results31 patients were included, 17 (54.8%) men and 14 (45.2%) women. Mean age at the time of surgery was 49.82 ± 18.8 years. The mean follow-up of the group was 31.56 ± 9.57 months (minimum = 19.6 months and maximum = 52.50months). As major complication one patient (3.23%) had a hard failure that required removal and re-implantation. 25.8% of the patients presented minor complications, the most frequent being vertigo/unsteadiness in 22.6%.The mean of language discrimination (free field at 65 dB SPL) was 62.19% ± 16.66; being 69.82% ± 7.35 in the group of severe to profound bilateral sensorineural hearing loss. A statistically significant reduction was observed in patients with tinnitus, assessed using the visual analog scale, preoperative = 7.2 ± 1,6 vs postoperative (18 months postoperative) = 1.7 ± 1.3 (p < 0.001). ConclusionsThe Nurotron™ cochlear implant shows satisfactory audiological results, in accordance with what has been reported in the literature. Minor complications were similar to previous studies, but the percentage of hard failure should continue to be observed, which was higher than other reports with comparable follow-up.

Evaluation of cochlear and auditory brainstem functions in COVID-19 patients; a case control study

BackgroundMany viral infections can cause hearing loss due to affection of cochlear hair cells or neurogenic pathway. Although, the damage secondary to viral infections is mainly cochlear affection; auditory brainstem can be affected as well. It was predicted that SARS-COV-2 infection can similarly affect the auditory system. This study aimed to detect affection in auditory system and if present investigate the possible site of lesion (up to the level of the brain stem) in relation to COVID-19 infection.MethodsThis is a case control study, where the study group constituted of thirty adults, diagnosed with COVID-19 at least 2 weeks prior to testing and up to 6 months, without previous auditory complaints pre-COVID-19 or other risk factors that could affect the auditory pathway. Fifteen adult participants that were age and gender matched to the study group with no previous history of covid-19 infection constituted the control group. Audiological evaluations done to all participants were pure-tone and speech audiometry, tympanometry, transient-evoked otoacoustic emission with and without contralateral suppression and auditory brainstem response measurements.ResultsThe study group showed significantly worse pure tone thresholds at high frequencies 4 and 8 kHz (p < 0.01), significantly worse transient-evoked otoacoustic emission signal to noise ratio at 2800 Hz and 4000 Hz (p < 0.05) and significantly lower total suppression index (p<0.05). On the other hand, there was no significant difference between both groups in auditory brainstem response wave latencies (p > 0.05).ConclusionCOVID-19 had subtle effect on cochlear basal turn, and it is shown that the auditory efferent system may also be affected, while the auditory nerve and afferent brainstem pathways seems to be spared. Moreover, the absence of the symptoms of auditory dysfunction postcovid-19 does not guarantee normal auditory functions.

A phase I/IIa safety and efficacy trial of intratympanic gamma-secretase inhibitor as a regenerative drug treatment for sensorineural hearing loss

Inhibition of Notch signalling with a gamma-secretase inhibitor (GSI) induces mammalian hair cell regeneration and partial hearing restoration. In this proof-of-concept Phase I/IIa multiple-ascending dose open-label trial (ISRCTN59733689), adults with mild-moderate sensorineural hearing loss received 3 intratympanic injections of GSI LY3056480, in 1 ear over 2 weeks. Phase I primary outcome was safety and tolerability. Phase lla primary outcome was change from baseline to 12 weeks in average pure-tone air conduction threshold across 2,4,8 kHz. Secondary outcomes included this outcome at 6 weeks and change from baseline to 6 and 12 weeks in pure-tone thresholds at individual frequencies, speech reception thresholds (SRTs), Distortion Product Otoacoustic Emissions (DPOAE) amplitudes, Signal to Noise Ratios (SNRs) and distribution of categories normal, present-abnormal, absent and Hearing Handicap Inventory for Adults/Elderly (HHIA/E). In Phase I (N = 15, 1 site) there were no severe nor serious adverse events. In Phase IIa (N = 44, 3 sites) the average pure-tone threshold across 2,4,8 kHz did not change from baseline to 6 and 12 weeks (estimated change −0.87 dB; 95% CI −2.37 to 0.63; P = 0.252 and −0.46 dB; 95% CI −1.94 to 1.03; P = 0.545, respectively), nor did the means of secondary measures. DPOAE amplitudes, SNRs and distribution of categories did not change from baseline to 6 and 12 weeks, nor did SRTs and HHIA/E scores. Intratympanic delivery of LY3056480 is safe and well-tolerated; the trial’s primary endpoint was not met.

Comparison of spectral resolution and spectro-temporal modulation sensitivity well above and near the hearing threshold

Spectral resolution and spectro-temporal modulation (STM) sensitivity both show a correlation with speech reception thresholds in noise. Both are also sensitive to the difficulties resulting from sensorineural hearing loss; however, the relationship between the two is not fully understood. The present study investigated the potential relationship between spectral resolution and STM sensitivity and the impact of presentation level in young, normal hearing listeners. Four noise carriers were tested with the two broader bandwidths and two 1-octave wide bandwidths: 200–6400 Hz, 1250–5000 Hz, 1250–2500 Hz, &amp; 2500–5000 Hz. Presentation levels were 70 dB SPL and 20 dB SL relative to the individual’s pure-tone frequency-shaped noise carrier threshold. Spectral resolution was tested using a phase reversal paradigm, also known as a spectral ripple discrimination task, with thresholds measured in cycles per octave. Spectral, temporal, and STM sensitivity were each tested using a depth detection task, with thresholds measured in dB. On a test-by-test case, results were aligned with past studies that included a single test. The results show that both sensitivities are distinct at a low presentation level close to individual hearing thresholds, and a mixed relationship between both measures indicate that spectral resolution may only be one contributor to STM sensitivity.

Exploring attentive listening in noise through the just-follow conversation task

Listening to a conversation demands comprehension, attention and prediction. To better understand the impact of these demands, as well as how hearing aids might alleviate them, a conversational listening test should be realistic, repeatable and relatable (i.e., have interpretable units). A test that potentially satisfies these needs is the just-follow conversation (JFC) task, where the listener adjusts the signal level to where they can understand, with effort, the gist of what is being said in a background of noise. Fifty-four participants sat in the centre of a circular loudspeaker array and adjusted the overall level of one monologue, one dialogue, two monologues or two dialogues presented in the front hemifield to where they could just follow the speech four times per trial. Signals were presented in surrounding fixed-level café and same-spectrum noise backgrounds. Bilateral hearing-aid users adjusted aided and unaided; non-users repeated each condition to evaluate reliability. Results showed an increase in JFC for dialogues re monologues. Individual JFC SNRs correlated with SSQ12 speech subscale scores as well as pure-tone threshold averages. JFC reliability was comparable to more objective speech understanding measures, but it may not be suitable to capture perceived conversational benefits for more subtle changes in hearing-aid processing. [Work supported by the UK Medical Research Council Grant No. MR/X003620/1 &amp; WS Audiology.]

Impact of unilateral vs. bilateral evaluation on cochlear implant candidacy

Background The indication criteria for cochlear implantation differ considerably across regions. Objectives To estimate the effects of different candidacy criteria on the number of cochlear implant (CI) candidates. Methods We analysed a very large clinical audiological database comprising pure-tone thresholds and speech-audiometric data in order to identify CI candidates on the basis of different audiometric candidacy criteria. In particular, we simulated the effects of three different CI candidacy criteria. Results The bilateral evaluation of CI candidacy has the strongest influence on the number of potential CI candidates. Additionally, the cut-off criteria for middle-ear implants have a large effect on numbers of candidates when air conduction has deteriorated. Conclusions and Significance: Expanding the indication criteria opens up the possibility of improving the accurate identification of individual cases suitable for cochlear-implant provision.

Soft Tissue Conduction Activates the Auditory Pathway in the Brain.

Soft tissue conduction is a mode of hearing which differs from air and bone conduction since the soft tissues of the body convey the audio-frequency vibrations to the ear. It is elicited by inducing soft tissue vibrations with an external vibrator applied to sites on the body or by intrinsic vibrations resulting from vocalization or the heartbeat. However, the same external vibrator applied to the skin sites also excites cutaneous mechanoreceptors, and attempts have been made to assist patients with hearing loss by audio-tactile substitution. The present study was conducted to assess the contribution of the auditory nerve and brainstem pathways to soft tissue conduction hearing. The study involved 20 normal hearing students, equipped with ear plugs to reduce the possibility of their response to air-conducted sounds produced by the external vibrator. Pure tone audiograms and speech reception (recognition) thresholds were determined in response to the delivery of the stimuli by a clinical bone vibrator applied to the cheek, neck and shoulder. Pure tone and speech recognition thresholds were obtained; the participants were able to repeat the words they heard by soft tissue conduction, confirming that the auditory pathways in the brain had been stimulated, with minimal involvement of the somatosensory pathways.

Vestibular function and hearing preservation in children following a minimally invasive cochlear implantation

PurposeThis retrospective cohort study aimed to investigate the effect of minimally invasive cochlear implantation (CI) on the vestibular function (VF) and residual hearing (RH) as well as their relationship in pediatric recipients before and after surgery.MethodsTwenty-four pediatric patients with preoperative low frequency residual hearing (LFRH) (250 or 500 Hz ≤ 80 dB HL) who underwent minimally invasive CI were enrolled. Pure-tone thresholds, the cervical/ocular vestibular-evoked myogenic potential (cVEMP/oVEMP), and video head impulse test (vHIT) were all evaluated in the 24 pediatric patients with preoperative normal VF before and at 1 and 12 months after surgery. The relationship between changes in hearing and VF was analyzed preoperatively and at 1 and 12 months postoperatively.ResultsThere were no significant differences on VF preservation and hearing preservation (HP) at both 1 and 12 months post-CI (p > 0.05). At 1 month post-CI, the correlations of the variations in vestibulo-ocular reflex (VOR) gains of horizontal semicircular canal (HSC) and posterior semicircular canal (PSC) and the shift in 250 Hz threshold were negatively correlated (r = − 0.41, p = 0.04 and r = − 0.43, p = 0.04, respectively). At 12 months post-CI, the shift in 250 Hz threshold negatively correlated to the variations in VOR gain of superior semicircular canal (SSC) (r = − 0.43, p = 0.04); the HP positively correlated to the variation in oVEMP-amplitude ratio (AR) (r = 0.41, p = 0.04).ConclusionOur study confirmed that there were partial correlations between VF preservation and HP both in the short- and long-terms after atraumatic CI surgery, especially with the 250 Hz threshold. Regarding the variation of PSC function, the correlation with hearing status was variable with time after atraumatic CI surgery. Minimally invasive techniques for HP are successful and effective for the preservation of VF in pediatric patients both in the short- and long-terms.