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Introduction Current Brazilian legislation requires that all workers exposed to noise are to be given an audiogram upon hiring, after 6 months of employment (first periodic test), and annually after the first periodic test. In other countries, the regulations of hearing conservation programs do not include the requirement for audiometric testing at 6 months of employment, but only annually. There is no evidence that the periodicity adopted by Brazilian legislation is the most appropriate. Objective The present study aimed to evaluate the first 3 occupational audiometric tests of workers exposed to noise. Methods Historical cohort study with cross-sectional analysis. Participants were all male metallurgy workers aged up to 40 years. The first 3 audiograms of each worker were analyzed: pre-employment audiometric test, periodic audiometric test 1, and periodic audiometric test 2. For each worker, mean frequency thresholds were calculated at 3, 4, and 6 kHz in the left and right ears for each test. Statistical analysis was performed using the nonparametric Wilcoxon test. Results A total of 988 workers were included. There was a significant difference in auditory thresholds between the pre-employment test and the 2 subsequent periodic tests for the right and left ears. There was no significant difference between Test1 and Test2 in either ear. Conclusion Given the lack of difference between the first 2 periodic tests, we believe that they could be merged into a single test, i.e., first periodic audiometric testing could be performed at 12 months of employment without compromising workers’ health.

OBJECTIVES In adult cochlear implant patients, conventional audiometry is used to measure postoperative residual hearing which requires active listening and patient feedback. However, audiological measurements in pediatric cochlear implant patients are both challenging as well as time consuming. Intracochlear electrocochleography (ECOG) offers an objective and a time-efficient method to measure frequency-specific cochlear microphonic or difference thresholds (CM/DIF) thresholds that closely approximate auditory thresholds in adult cochlear implant patients. The correlation between CM/DIF and behavioral thresholds has not been established in pediatric cochlear implant patients. In the present study, CM/DIF thresholds were compared with audiometric thresholds in pediatric cochlear implant patients with postoperative residual hearing. DESIGN Thirteen (11 unilateral and 2 bilateral) pediatric cochlear implant patients (mean age = 9.2 years ± 5.1) participated in this study. Audiometric thresholds were estimated using conventional, condition play, or visual reinforcement audiometry. A warble tone stimulus was used to measure audiometric thresholds at 125, 250, 500, 1000, and 2000 Hz. ECOG waveforms were elicited using 50-msec acoustic tone-bursts. The most apical intracochlear electrode was used as the recording electrode with an extra-cochlear ground electrode. The ECOG waveforms were analyzed to determine CM/DIF thresholds that were compared with pediatric cochlear implant patients' audiometric thresholds. RESULTS The results show a significant correlation (r = 0.77, p < 0.01) between audiometric and CM/DIF thresholds over a frequency range of 125 to 2000 Hz in pediatric cochlear implant patients. Frequency-specific comparisons revealed a correlation of 0.82, 0.74, 0.69, 0.41, and 0.32 between the audiometric thresholds and CM/DIF thresholds measured at 125, 250, 500, 1000, and 2000 Hz, respectively. An average difference of 0.4 dB (±14 dB) was measured between the audiometric and CM/DIF thresholds. CONCLUSIONS Intracochlear ECOG can be used to measure CM/DIF thresholds in pediatric cochlear implant patients with residual hearing in the implanted ear. The CM/DIF thresholds are similar to the audiometric thresholds at lower test frequencies and offer an objective method to monitor residual hearing in difficult-to-test pediatric cochlear implant patients.

Objectives - to study hearing thresholds at high frequencies in elderly and senile patients, taking into account the age norm and the presence of comorbid diseases. Material and methods. 111 patients aged from 50 to 97 years (mean age 70.5 ± 2.1) were examined, their age, auditory function, and concomitant diseases were also registered. Results. The measured average auditory thresholds at high frequencies, if compared to the age-related standards for auditory sensitivity, have revealed an underestimated hearing loss in 12.6% of patients. The presence of concomitant diseases has a significant impact on the development of chronic sensorineural hearing loss in each age group. Conclusion. Audiometry in an extended frequency range in elderly patients with concurrent diseases can improve the hearing examination algorithm.

Introduction Cortical auditory evoked potentials (CAEPs) can be used to evaluate both peripheral and cortical components of auditory function, and contribute to the assessment of functional sensitivity and auditory thresholds, especially in neonates and infants. Auditory evoked potentials reflect auditory maturity and precede the acquisition of more complex auditory and cognitive skills, and are therefore crucial for speech and language development. Objective The aim of the present study was to determine the presence, latency and amplitude of CAEP components in response to verbal stimuli in children aged 2 years old. Methods The sample consisted of 19 subjects, 10 of whom were male while 9 were female. All of the participants were 24 months old at the time of assessment. Results A total of 17 of the participants displayed all components of the CAEP. Additionally, no significant differences were observed between genders or ears in the present sample. The presence of all components of the CAEP in subjects aged 2 years old confirms the existence of a critical period for the maturation of auditory pathways in the first 2 years of life. Conclusion In the present study, in addition to the P1/N1 components, it was possible to observe the presence of the CAEP P2/N2 components in individuals aged 24 months, confirming the existence of a critical period for the maturation of the auditory pathways in the first 2 years of life.

With developments in science and technology, the number of electric vehicles will increase, and they will even replace ICE vehicles. Thus, perceiving the presence of approaching electric vehicles on the road has become an important issue. In this study, the auditory detectability of the electric vehicle warning sound at different volumes, distances, and environmental noise levels was investigated. To this end, the detection rate was recorded in experiments with three environmental noise levels (50, 60, and 70 dBA), two sound pressure levels (SPLs) of the warning sound (46 and 51 dBA), three frequency combinations of the warning sound (5000, 2500, 1250, and 630 Hz for high frequencies, 2500, 1250, 630, and 315 Hz for medium frequencies, and 1250, 630, 315, and 160 Hz for low frequencies), and five distances (2, 4, 6, 8, and 10 m). The main results showed that the detection rate at 51 dBA was significantly higher than that at 46 dBA under a high-frequency warning sound, however, the detection rates were similar under medium- and low-frequency warning sounds. The participants’ rates of detection for warning sounds were less than 20% under all experimental conditions, and a high-frequency warning sound was not affected by environmental noise. With regard to distances, no significant effects were observed between the distances and the detection rate at any of the three frequencies. In addition, auditory thresholds based on high-, medium-, and low-frequency warning sounds were found through logistic regression analysis results. The results of this study can be used as a reference for the future design of warning sounds.

Belgian Waterslager song canaries, bred for hundreds of years for a low-pitched song, have also acquired an inherited high-frequency hearing loss associated with hair cell abnormalities. Here, auditory thresholds measured using auditory brainstem responses and psychophysical methods in three different strains of canaries are compared: Belgian Waterslagers, American Singers, and Borders. Border canaries have not been bred for song characteristics while American Singer canaries have been bred for song only since the 1930s. Results show that American Singer canaries also have elevated high frequency thresholds that are similar to those of the Belgian Waterslager, while Border canaries have normal thresholds. These results strengthen the case that song canary breeders in selecting for song characteristics may have inadvertently selected for hearing abnormalities.

Brainstem auditory evoked potentials (BAEP) are useful to diagnose neurologic and genetic disorders in cattle but normal parameters and its application to detect changes in hearing are not demonstrated. The aims of this study were to develop a protocol for obtaining BAEP in Holstein calves and to establish the normal parameters of peak latencies, interpeak latencies (IPL) and waveforms of BAEP in this species. Ten male Holstein calves, aged 2.5 months and weighting 90.7 ± 4.0 kg were used. All animals were previously sedated with 0.08 mg/kg xylazine hydrochloride administered intramuscularly. The BAEP analysis was recorded using the IHS SmartEP-ASSR program connected with electrode needles placed on the standardized locations of the animal's head. Monoaurally presented broadband click stimuli (0.1 ms) were used for BAEP stimulation, with contralateral masking of 30 dB SPL. Stimuli were presented at a rate of 35.5 pulses per second (PPS) and evoked responses were collected and averaged 450–1500 times for each sound intensity. Earphones were inserted into the ear canal to present the acoustic stimulus and to attenuate environmental noise. Peak latencies, IPL, waveforms and auditory thresholds were recorded and analyzed in the right ear and were like those described in previous papers in adult male bulls. Auditory thresholds obtained in all animals were 33 ± 1.5 dB SPL. Peak latencies were 1.4 ± 0.07 ms (Peak I), 2.4 ± 0.10 ms (Peak II), 3.3 ± 0.10 ms (Peak III), 4.4 ± 0.19 ms (Peak IV) and 5.6 ± 0.28 ms (Peak V). IPL were 1.9 ± 0.12 ms (IPL I-III), 4.1 ± 0.29 ms (IPL I-V), 2.2 ± 0.19 ms (IPL II-V) and 2.2 ± 0.19 ms (IPL III-V). Brainstem auditory evoked potentials are a minimally-invasive method to evaluate level of audition in Holstein calves. In addition, BAEP is a method that can be applied in young calves and it would work on-farm to select the animals with better conditions.

The study of defense behavior development in pied flycatcher altricial nestlings has shown that preceding visual deprivation decreased the capability to freeze in the young. At the same time, auditory thresholds of deprived nestlings were lower than those of the nestlings developing in unaltered visual environment. Our goal in the present work was to study effects of visual input on the functional development of neural circuitry for flycatcher’s acoustically-guided defensive behavior. We compared the immunohistochemical response of transcription factors ZENK and c-Fos in the nestlings’ auditory telencephalic structures in visually deprived and non-deprived flycatcher nestlings to alarm calls emitted by adult birds. We have demonstrated that the development of flycatcher nestlings under the conditions of limited visual afferentation results in the decrease of induction of the immediate-early genes c-Fos and ZENK in auditory structures of 9-day-old nestlings performing auditory-guided defense behavior. The most marked decrease of induction of both genes is observed in Field L. Our data suggest that visual afferentation affects neuronal activations in higher auditory structures of nestlings’ brain that, in turn, may increase the efficiency of species-typical alarm call. Thus, the work demonstrated for the first time that visual affererntation facilitates the growth of efficiency of alarm call affecting the activity of neurons in auditory integrative structures.

OBJECTIVES/HYPOTHESIS Previous studies have demonstrated that electrocochleography (ECochG) measurements made at the round window prior to cochlear implant (CI) electrode insertion can account for 47% of the variability in 6-month speech perception scores. Recent advances have made it possible to use the apical CI electrode to record intracochlear responses to acoustic stimuli. Study objectives were to determine 1) the relationship between intracochlear ECochG response amplitudes and 6-month speech perception scores and 2) to determine the relationship between behavioral auditory thresholds and ECochG threshold estimates. The hypothesis was that intracochlear ECochG response amplitudes made immediately after electrode insertion would be larger than historical controls (at the extracochlear site) and explain more variability in speech perception scores. STUDY DESIGN Prospective case series. METHODS Twenty-two adult CI recipients with varying degrees of low-frequency hearing had intracochlear ECochG measurements made immediately after CI electrode insertion using 110 dB SPL tone bursts. Tone bursts were centered at five octave-spaced frequencies between 125 and 2,000 Hz. RESULTS There was no association between intracochlear ECochG response amplitudes and speech perception scores. But, the data suggest a mild to moderate relationship between preoperative behavioral audiometric testing and intraoperative ECochG threshold estimates. CONCLUSION Performing intracochlear ECochG is highly feasible and results in larger response amplitudes, but performing ECochG before, rather than after, CI insertion may provide a more accurate assessment of a patient's speech perception potential. LEVEL OF EVIDENCE 4 Laryngoscope, 131:E2681-E2688, 2021.

Studies of genetic disorders of sensorineural hearing loss have been instrumental in delineating mechanisms that underlie the remarkable sensitivity and selectivity that are hallmarks of mammalian hearing. For example, genetic modifications of TECTA and TECTB, which are principal proteins that comprise the tectorial membrane (TM), have been shown to alter auditory thresholds and frequency tuning in ways that can be understood in terms of changes in the mechanical properties of the TM. Here we investigate effects of genetic modification targeting CEACAM16, a third important TM protein. Loss of CEACAM16 has been recently shown to lead to progressive reductions in sensitivity. While age-related hearing losses have previously been linked to changes in sensory receptor cells, the role of the TM in progressive hearing loss is largely unknown. Here, we show that TM stiffness and viscosity are significantly reduced in adult mice that lack functional CEACAM16 relative to age-matched wild-type controls. By contrast, these same mechanical properties of TMs from juvenile mice that lack functional CEACAM16 are more similar to those of wild-type mice. Thus changes in hearing phenotype align with changes in TM material properties and can be understood in terms of the same TM wave properties that were previously used to characterize modifications of TECTA and TECTB. These results demonstrate that CEACAM16 is essential for maintaining TM mechanical and wave properties, which in turn, are necessary for sustaining the remarkable sensitivity and selectivity of mammalian hearing with increasing age.

It has been suggested that infants respond preferentially to infant-directed speech because their auditory sensitivity to sounds with extensive frequency modulation (FM) is better than their sensitivity to less modulated sounds. In this experiment, auditory thresholds for FM tones and for unmodulated, or pure, tones in a background of noise were measured for 4-month-old infants using a conditioned response procedure. The FM tones swept from 150 to 275 Hz or from 150 to 550 Hz. The frequency of the pure tone was either 275 or 550 Hz. The results showed that infants were slightly, but significantly, more sensitive to the sounds that included 550 Hz than they were to the lower frequency sounds, whether or not the sound was frequency modulated. It appears that infants could be somewhat more sensitive to infant-directed than to adult-directed speech, not because of FM per se, but because the fundamental frequency excursions in infant-directed speech extend into a higher frequency range than those in adult-directed speech.

Purpose: to investigate the auditory recognition of intermittent speech in relation to different modulation rates and ages. Methods: 20 young people, 20 middle-aged adults, and 16 older adults, all of them with auditory thresholds equal to or lower than 25 dB HL up to the frequency of 4000 Hz. The participants were submitted to intermittent speech recognition tests presented in three modulation conditions: 4 Hz, 10 Hz, and 64 Hz. The percentages of correct answers were compared between age groups and modulation rates. ANOVA and post hoc tests were conducted to investigate the modulation rate effect, and the mixed linear regression model (p < 0.001). Results: regarding the age effect, the data showed a significant difference between young people and older adults, and between middle-aged and older adults. As for the modulation rate effect, the indexes of correct answers were significantly lower at the slower rate (4 Hz) in the three age groups. Conclusion: an age effect was verified on intermittent speech recognition: older adults have greater difficulty. A modulation rate effect was also noticed in the three age groups: the higher the rate, the better the performance. RESUMO Objetivo: investigar o reconhecimento auditivo da fala intermitente em função de diferentes taxas de modulação e em função da idade. Métodos: participaram do estudo vinte jovens, vinte adultos de meia idade, e dezesseis idosos, todos com limiares auditivos iguais ou menores que 25 dB NA até a frequência de 4000 Hz. Os participantes foram submetidos a testes de reconhecimento da fala intermitente apresentada em três condições de modulação: 4 Hz, 10 Hz e 64 Hz. Percentuais de acerto foram comparados entre grupos etários e taxas de modulação. Para a investigação do efeito da taxa de modulação foi realizada ANOVA e testes Post Hoc, enquanto para a investigação do efeito da idade, utilizou-se o modelo de regressão linear misto (p

Purpose This article investigates the validity of a smartphone-based audiometry for hearing screening to identify hearing loss in workers exposed to noise. Research Design This is a validation study comparing hearing screening with the hearTest to conventional audiometry. The study population included all workers who attended the Brazilian Social Service of Industry to undergo periodic examinations. Sensitivity, specificity, the Youden index, and positive (PPV) and negative predictive values (NPV) for hearing screening obtained by the hearTest were estimated according to three definitions of hearing loss: any threshold greater than 25 dB hearing level (HL), the mean auditory thresholds for 0.5, 1, 2, and 4 kHz greater than 25 dB HL, and the mean thresholds for 3, 4, and 6 kHz greater than 25 dB HL. Note that 95% confidence intervals were calculated for all measurements. Results A total of 232 workers participated in the study. Hearing screening with the hearTest presented good sensitivity (93.8%), specificity (83.9%), and Youden index (77.7%) values, a NPV (97.2%), and a low PPV (69.0%) for the identification of hearing loss defined as any auditory threshold greater than 25 dB HL. For the other definitions of hearing loss, we observed high specificity, PPV and NPV, as well as low sensitivity and Youden index. Conclusion The hearTest is an accurate hearing screening tool to identify hearing loss in workers exposed to noise, including those with noise-induced hearing loss, although it does not replace conventional audiometry.

Purpose Auditory threshold estimation using the auditory brainstem response or auditory steady state response is limited in some populations (e.g., individuals with auditory neuropathy spectrum disorder [ANSD] or those who have difficulty remaining still during testing and cannot tolerate general anesthetic). However, cortical auditory evoked potentials (CAEPs) can be recorded in many such patients and have been employed in threshold approximation. Thus, we studied CAEP estimates of auditory thresholds in participants with normal hearing, sensorineural hearing loss, and ANSD. Method We recorded CAEPs at varying intensity levels to speech (i.e., /ba/) and tones (i.e., 1 kHz) to estimate auditory thresholds in normal-hearing adults ( n = 10) and children ( n = 10) and case studies of children with sensorineural hearing loss and ANSD. Results Results showed a pattern of CAEP amplitude decrease and latency increase as stimulus intensities declined until waveform components disappeared near auditory threshold levels. Overall, CAEP thresholds were within 10 dB HL of behavioral thresholds for both stimuli. Conclusions The above findings suggest that CAEPs may be clinically useful in estimating auditory threshold in populations for whom such a method does not currently exist. Physiologic threshold estimation in difficult-to-test clinical populations could lead to earlier intervention and improved outcomes.

Animal hearing has long served as a model for understanding human hearing. Yet conversely, animal hearing can only be imagined through human hearing. This chapter shows how, building on techniques for testing human hearing, experimental psychologists in the 1930s and 1940s turned to determining the absolute (upper) frequencies of hearing for various other mammal subjects. Showing the domains of animal auditory perception to be overlapping but rarely congruous with that of humans, these measurements began to lead lives of their own in the subsequent decades. Propelled by various scientific, military, and commercial interests, fascination with the ultrasonic stirred imaginaries of sonic control. The threshold of hearing, this chapter argues, is also a threshold to the imagination, as expressed in the simultaneous success and failure of mundane technologies such as the “Ultrasonic Pied Piper” or the “Bird-E-Vict.”

Distortion-product otoacoustic emissions (DPOAEs) emerge from the cochlea when elicited with two tones of frequencies f1 and f2. DPOAEs mainly consist of two components, a nonlinear-distortion and a coherent-reflection component. Input-output (I/O) functions of DPOAE pressure at the cubic difference frequency, f DP = 2 f 1 − f 2, enable the computation of estimated distortion-product thresholds (EDPTs), offering a noninvasive approach to estimate auditory thresholds. However, wave interference between the DPOAE components and suboptimal stimulus-level pairs reduces the accuracy of EDPTs. Here, the amplitude P of the nonlinear-distortion component is extracted from short-pulse DPOAE time signals. DPOAE level maps representing the growth behavior of P in L 1 , L 2 space are recorded for 21 stimulus-level pairs and 14 frequencies with f 2 = 1 to 14 kHz ( f 2 / f 1 = 1.2) from 20 ears. Reproducing DPOAE growth behavior using a least-squares fit approach enables the derivation of ridge-based I/O functions from model level maps. Objective evaluation criteria assess the fit results and provide EDPTs, which correlate significantly with auditory thresholds (p

Background Sensory gating is a measure used to evaluate inhibitory deficits underlying neurological disorders. However, the effects of hearing loss (HL), thought to decrease inhibition, remain unknown on gating function. Purpose The goal of this study was to investigate gating performance in HL. Research Design This was a prospective, cross-sectional study with independent group comparison and correlational design. Study Sample Eleven adults (mean age/standard deviation = 47.546 ± 7.967 years) with normal hearing (NH) and 11 adults (mean age/standard deviation = 56.273 ± 13.871 years) with mild–moderate high-frequency HL. Data Collection and Analysis Cortical auditory evoked potentials (CAEPs) were recorded in response to tonal pairs via high-density electroencephalography. The CAEP response to the second tone in the pair (S2) was compared with the response to the first tone in the pair (S1) within groups. Amplitude gating indices were compared between groups and correlated with auditory behavioral measures. Current density reconstructions were performed to estimate cortical gating generators. Results Amplitude gating indices were decreased and correlated with elevated auditory thresholds. Gating generators in temporal, frontal, and prefrontal regions were localized in the NH group, while HL gating was localized in mainly temporal and parietal areas. Conclusions Reduced inhibition may be associated with compensatory cortical gating networks in HL and should be considered when utilizing gating in clinical populations.

BACKGROUND Several health conditions among professional fishermen have been reported. Among the risks to the health of fishermen, it should be noted that high noise levels cause hearing loss and general health problems. OBJECTIVE to investigate the effects of exposure to occupational noise on hearing in professional fishermen at the main large-scale commercial fishing center in Brazil. METHODS A cross-sectional study, 466 Brazilian commercial fishermen participated in the study, all males, ages range 18-67 years. A total of 15 vessels were included in the study. The first phase involved assessment of the sound pressure levels (SPLs) in the vessels, the second phase involved the use of a questionnaire and audiological assessment. RESULTS Most compartments registered SPLs greater than 80 dBA and the noisiest compartment was the engine-room, where the vessel pilot works. Among the fishermen, tinnitus was the most commonly reported symptom (48.63%). A higher prevalence of hearing loss was observed in engine-room keepers. Longer the length of time in service, and consequently, exposure to noise (in years), were associated with higher auditory thresholds. CONCLUSION the tolerance limits to noise exposure were exceeded according to legislation. Fishing activities are associated with noise-induced hearing loss, with the risk increasing with the length of service.

Background Auditory evoked potentials (AEPS) constitutes the most commonly used neurophysiological test to assess the functional development of the auditory brainstem in infants and allows the evaluation of hearing for high frequencies. Methods An observational, descriptive, cross-sectional and retrospective study was conducted. The AEPS results for 186 infants (372 ears) with a history of prematurity were examined. The bioelectrical response, morphology, amplitude, latencies I, III and V, and intervals I-III, III-V and I-V were compared, as well as auditory thresholds between two groups of premature infants Results The bioelectrical response, latencies I, III and V, and intervals I-III and III-V were similar between the two groups of premature infants according to their corrected age; no statistically significant differences were found (p > 0.05) for these variables. The amplitude, morphology, and the I-V interval were more affected in the group of premature infants Conclusions The functional development of the auditory brainstem was similar between the groups of premature infants and within the normal range for the respective corrected age. Prematurity produced a directly proportional and statistically significant increase in the frequency of hearing loss for high frequencies.

Background: Auditory steady-state response (ASSR) is a test for the estimation of auditory thresholds. It is used in infants, children, and adults. This case report presented unusual ASSR results in an elderly person. The Case: Pure tone and speech audiometry, tympanometry and acoustic reflexes showed a moderate sensorineural hearing loss in both ears. However, the patient did not respond in the ASSR test to different carrier frequencies with frequency modulations of 40 and 80 Hz. Conclusion: To date, the results of the different effects of the aging process obtained from ASSR responses have been reported. However, the absence of any response in the ASSR test has never been reported. The patient in this case report may have these results because of a neural deficit. Keywords: Sensorineural hearing loss; aging; auditory steady-state response

We aimed to evaluate whether electrophysiological auditory thresholds (EATs) before 3 month of age, as assessed by the auditory brainstem responses (ABR) test and the auditory steady state responses (ASSR) test, can predict hearing outcome at 3 years of age among children born with congenital cytomegalovirus (cCMV) infection. Audiological assessment was performed before 3 months of age, and every 6 months thereafter until 3 years of age, in a population of 63 children (126 ears). EATs before 3 months of age and at 3 years of age were compared. No ear with an EAT of ≤30 dBHL (i.e. normal hearing) before 3 months of age showed worsening EATs at 3 years of age. An EAT of ≤30 dBHL obtained by ABR and ASSR tests before 3 months of age is predictive of a normal hearing at 3 years of age in children born with cCMV.

Purpose: to describe the audiological profile of professional disc jockeys acting in cities of the Brazilian Federal District. Methods: audiometry, tympanometry, transient evoked emissions, and distortion product evoked emissions exams were conducted, as well as interviews, in order to identify auditory symptoms. Appropriate statistical tests were applied, adopting a significance level lower than 0.05. Results: a total of 21 disc jockeys, aged between 20 and 45 years, were evaluated. The most cited auditory complaints were feeling of ear fullness (86%) and tinnitus (57%). Auditory thresholds remained predominantly within normal range (90%), but thresholds were increased in frequencies from 3 KHz to 6 KHz (38%). Only 42% of the sample presented a pass response in transient evoked emissions, and 81% in distortion product evoked emissions, in both ears. Conclusion: the research identified auditory thresholds predominantly within standards of normality, though with increased high frequencies, that may be associated with noise exposure. The otoacoustic emissions presented alterations both in the transient ones and in the distortion product. RESUMO Objetivo: descrever o perfil audiológico de profissionais disc jockeys atuantes em cidades do Distrito Federal. Métodos: foram realizados os exames de audiometria, timpanometria, emissões evocadas por estímulo transiente e emissões evocadas - produto de distorção, e entrevista para identificar sintomas auditivos. Foram aplicados os testes estatísticos pertinentes adotando o nível de significância menor que 0,05. Resultados: foram avaliados 21 disc jockeys com faixa etária entre 20 e 45 anos. As queixas auditivas mais citadas foram sensação de plenitude auricular (86%) e zumbido (57%). Os limiares auditivos mantiveram-se predominantemente dentro da normalidade (90%), mas houve aumento dos limiares nas frequências de 3.000 a 6.000 Hz (38%). Apenas 42% da amostra apresentaram resposta “passa” nas emissões evocadas por estímulo transiente e 81% nas emissões evocadas - produto de distorção em ambas as orelhas. Conclusão: a pesquisa identificou limiares auditivos predominantemente dentro dos padrões de normalidade, entretanto com aumento das frequências altas, que podem estar associadas à exposição ao ruído. As emissões otoacústicas apresentaram alterações tanto nas transientes quanto nas por produto de distorção.

Naked mole-rats are extremely social and extremely vocal rodents, displaying a wide range of functionally distinct call types and vocalizing almost continuously. Their vocalizations are low frequency, and a behavioral audiogram has shown that naked mole-rats, like other subterranean mammals, hear only low frequencies. Hence, the frequency range of their hearing and vocalizations appears to be well matched. However, even at low frequencies, naked mole-rats show very poor auditory thresholds, suggesting vocal communication may be effective only over short distances. However, in a tunnel environment where low frequency sounds propagate well and background noise is low, it may be that vocalizations travel considerable distances at suprathreshold intensities. Here, we confirmed hearing sensitivity using the auditory brainstem response; we characterized signature and alarm calls in intensity and frequency domains and we measured the effects of propagation through tubes with the diameter of naked mole-rat tunnels. Signature calls-used for intimate communication-could travel 3-8 m at suprathreshold intensities, and alarm calls (lower frequency and higher intensity), could travel up to 15 m. Despite this species' poor hearing sensitivity, the naked mole-rat displays a functional, coupled auditory-vocal communication system-a hallmark principle of acoustic communication systems across taxa.

OBJECTIVE. Inventing of the system of auditory brainstem implantation. MATERIAL AND METHODS. 3 patients were chosen for study: 2 adults with neurofibromatosis of type II and a 2 years old child with bilateral cochlea aplasia. RESULTS. In the end of the first rehabilitation, the auditory thresholds accounted 45–50 dB. In 2 years after surgery, the adults differentiate words from the closed set. Passive vocabulary of the child amounted for 200 words. Speech intelligibility was 30–70 % in these patients. CONCLUSION. Wearing of auditory processor for five months led to significant dynamics.

This study was performed to assess whether there is an association between elevated Fasting Blood Glucose (FBG) and hearing impairment in Bangladeshi population. A total of 142 subjects (72 with elevated FBG; 70 control) were included in the study. The mean auditory thresholds of the control subjects at 1, 4, 8 and 12 kHz frequencies were 6.35 ± 0.35, 10.07 ± 0.91, 27.57 ± 1.82, 51.28 ± 3.01 dB SPL (decibel sound pressure level), respectively and that of the subjects with elevated FBG were 8.33 ± 0.66, 14.37 ± 1.14, 38.96 ± 2.23, and 71.11 ± 2.96 dB, respectively. The auditory thresholds of the subjects with elevated FBG were significantly (p 10 years) showed significantly (p 40 years) and younger (≤40 years) age groups compared to the respective controls. The binary logistic regression analysis showed a 5.79-fold increase in the odds of extra-high frequency hearing impairment in diabetic subjects after adjustment for age, gender and BMI. This study provides conclusive evidence that auditory threshold at an extra-high frequency could be a sensitive marker for hearing impairment in diabetic subjects.

Tympanic middle ears are key innovations in the evolution of terrestrial hearing. These structures facilitate sound transmission between air and the inner ear, across an impedance mismatch boundary. Nontympanic taxa present an opportunity to explore extratympanic hearing mechanisms, which could inform our understanding of terrestrial hearing evolution. Salamanders are useful models in this regard because they lack tympanic middle ears. Lung-based extratympanic auditory mechanisms have been demonstrated in earless anurans and are hypothesized to apply to salamanders, based on observations that the body walls overlying the lungs vibrate in response to airborne sound. We tested the hypothesis that body wall vibrations over the lungs aid aerial hearing in salamanders. We immersed the body walls and pectoral girdle below a water surface in two lunged species, Notophthalmus viridescens and Ambystoma talpoideum, predicting that this would elevate auditory thresholds (measured using evoked potentials) by...

Military operations often require Service Members (SMs) to make life-and-death decisions based on information they can only obtain auditorily. However, the wide variety of critical sounds, essential spoken messages, and masking environments encountered while performing military missions makes it difficult to use clinical tests to predict the operational performance of hearing-impaired SMs. In this study, ≈2400 SMs performed listening tasks derived from binaural recordings made during realistic battlefield exercises at the US Army Joint Readiness Training Center. The listening tasks included standardized speech recognition tasks based on the Oldenburg Matrix Test and Modified Rhyme Test (MRT), as well as scenario-based multiple-choice tasks where questions were asked about unmodified verbal exchanges that occurred between SMs engaged in the battlefield simulation. The scores SMs achieved on these operational tasks were then compared to their hearing thresholds and to their scores on the MRT80. The results show that an auditory fitness-for-duty standard that requires individuals with thresholds that exceed the values defined in the new US Army H3 Profile to obtain a minimum score on the MRT80 is generally able to identify individuals who are most at risk of performing abnormally poorly on militarily relevant listening tasks. [The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of the Army, Department of Defense, or U.S. Government.]