Acoustic reflexes: should we be paying more attention?

OBJECTIVE: The clinical audiology test battery often involves playing physically simple sounds with questionable ecological value to the listener. In this technical report, we revisit how valid this approach is using an automated, involuntary auditory response; the acoustic reflex threshold (ART). DESIGN: The ART was estimated four times in each individual in a quasi-random ordering of task conditions. The baseline condition (referred to as Neutral) measured the ART following a standard clinical practice. Three experimental conditions were then used in which a secondary task was performed whilst the reflex was measured: auditory attention, auditory distraction and visual distraction tasks. STUDY SAMPLE: Thirty-eight participants (27 males) with a mean age of 23 years were tested. All participants were audiometrically healthy. RESULTS: The ART was elevated when a visual task was performed at the same time as the measurements were taken. Performing an auditory task did not affect the ART. CONCLUSIONS: These data indicate that simple audiometric measures widely used in the clinic, can be affected by central, non-auditory processes even in healthy, normal-hearing volunteers. The role of cognition and attention on auditory responses will become ever more important in the coming years.

The effect of cochlear implant age and duration of intervention on ESRT in children with cochlear implant.

OBJECTIVE: To study the effect of cochlear implant age and duration of the intervention (auditory rehabilitation post-cochlear implantation) on ESRT in children with cochlear implants. METHODS: A total of 90 pre-lingual cochlear implant users were included. For the measurement of ESRTs the recipient's processor was connected to the programming pod and electrode numbers 22, 11 and 3 (apical, middle and basal), respectively, were activated to give stimulation sequentially and elicit deflection as a response. RESULTS: There were significant differences in the measured T, C and ESRT levels with respect to the duration of the intervention (auditory rehabilitation post-cochlear implantation) and cochlear implant age obtained at p < 0.05*, 0.01**. DISCUSSION: The differences in the T, C and ESRT levels after continued device usage and after attending auditory rehabilitation sessions post-cochlear implantation are subjected to optimal benefit from implantation during the critical period. CONCLUSION: The differences in T, C and ESRT levels can be utilised clinically to study the importance of duration of cochlear implant device usage and the importance of auditory rehabilitation post-cochlear implantation in children with cochlear implantation.

Study of auditory pathways in type 1 diabetes mellitus through brainstem auditory evoked potentials and contralateral acoustic reflex.

PURPOSE: To investigate the functionalities of the neural pathways through the auditory evoked potentials of the brainstem and the contralateral stapedial acoustic reflexes in normal-hearing individuals with type 1 diabetes mellitus, in order to detect possible alterations in the central auditory pathways. METHODS: This is a cross-sectional study with a comparison group and a convenience sample, consisting of 32 individuals with type 1 diabetes mellitus and 20 controls without the disease. All subjects had hearing thresholds within normal limits and type A tympanometric curves. The acoustic reflex arc and brainstem auditory potentials were investigated. Statistical analyses were performed using the SPSS 17.0. The Chi-square test, Student´s t-test, and Multiple linear regression were used. RESULTS: The auditory thresholds of the acoustic reflex were statistically lower in the group with the disease at frequencies of 0.5 kHz and 1.0 kHz in the left ear (p=0.01 and p=0.01, respectively). The absolute latencies III and V of the auditory potentials of the brainstem in the right ear and V in the left ear were increased in subjects with type 1 diabetes mellitus (p=0.03, p=0.02 and p=0.03, respectively). CONCLUSION: The findings suggest that subjects with type 1 diabetes mellitus are more likely to present alterations in the central auditory pathways, even with auditory thresholds within normal limits.

Accessing the stapedius muscle via novel surgical retrofacial approach during cochlear implantation surgery: Intraoperative results on feasibility and safety.

Human stapedius muscle (SM) can be directly and safely accessed via retrofacial approach, opening new approaches to directly measure the electrically evoked stapedius reflex threshold (eSRT). The measurement of the SM activity via direct surgical access represents a potential tool for objective eSRT fitting of cochlear implants (CI), increasing the benefit experienced by the CI users and leading to new perspectives in the development of smart implantable neurostimulators. 3D middle-ear reconstructions created after manual segmentation and related SM accessibility metrics were evaluated before the CI surgery for 16 candidates with assessed stapedius reflex. Retrofacial approach to access the SM was performed after facial recess exposure. In cases of poor exposition of SM, the access was performed anteriorly to the FN via drilling of the pyramidal eminence (PE). The total access rate of the SM via both the retrofacial and anterior approach of the FN was 100%. In 81.2% of cases (13/16), the retrofacial approach allowed to access the SM on previously categorized well exposed (8/8), partially exposed (4/5), and wholly concealed (1/3) SM with respect to FN. Following intraoperative evaluation in the remaining 18.8% (3/16), the SM was accessed anteriorly via drilling of the PE. Exposure of SM with respect to the FN and the sigmoid sinus's prominence was a predictor for the suitable surgical approach. The retrofacial approach offers feasible and reproducible access to the SM belly, opening direct access to electromyographic sensing of the eSRT. Surgical planner tools can quantitatively assist pre-surgical assessment.

A BK channel-targeted peptide induces age-dependent improvement in behavioral and neural sound representation.

Recent evidence suggests that modulation of the large-conductance, calcium-activated potassium (BK) channel regulates auditory processing in the brain. Because ion channel expression often changes during aging, this could be a factor in age-related hearing loss. The current study explored how the novel BK channel modulator LS3 shapes central auditory processing in young and old adult mice. In vivo extracellular recordings in the auditory midbrain demonstrated that LS3 differentially modulates neural processing along the tonotopic axis. Though sound-evoked activity was reduced in the mid and ventral tonotopic regions, LS3 enhanced excitatory drive and sound-evoked responses for some neurons in the dorsal, low-frequency region. Behavioral assessment using acoustic reflex modification audiometry indicated improved tone salience following systemic LS3 administration. Moderation of these responses with aging correlated with an age-related decline in BK channel expression. These findings suggest that targeting the BK channel enhances responsivity to tonal sounds, providing the potential to improve hearing acuity and treat hearing loss.

The optimal probe tone frequency for eSRT measurements at individual electrodes in children with cochlear implants.

BACKGROUND: Higher probe tone frequencies have been shown to increase the elicitation rates in electrically evoked stapedius reflex threshold (eSRT) measurements. OBJECTIVES: To determine the optimal probe tone frequency for contralateral eSRT measurements at individual electrodes in children with unilateral cochlear implants and to assess the relationship between eSRTs for this frequency and most comfortable levels (M-levels). MATERIALS AND METHODS: Contralateral eSRT measurements with three probe tone frequencies (226, 678, and 1000 Hz) at individual electrodes were performed on 26 paediatric Advanced Bionics cochlear implant recipients. RESULTS: The elicitation rates of eSRTs for 226, 678, and 1000 Hz probe tones were 73.08% (57/78), 88.46% (69/78), and 88.46% (69/78), respectively. The average eSRT for the 1000 Hz probe tone was significantly lower than those for 226 and 678 Hz probe tones (p<.001 and p=.009, respectively). ESRTs for the 1000 Hz probe tone and M-levels were significantly correlated at all tested electrodes (all p<.001). CONCLUSIONS AND SIGNIFICANCE: The optimal probe tone frequency for contralateral eSRT measurement at individual electrodes in children with unilateral cochlear implants is 1000 Hz. ESRTs for the 1000 Hz probe tone are significantly correlated with M-levels and can be used to guide the M-levels setting in these children.

Effect of Number of Electrodes Used to Elicit Electrical Stapedius Reflex Thresholds in Cochlear Implants.

INTRODUCTION: When mapping cochlear implant (CI) patients with limited reporting abilities, the lowest electrical stimulus level that produces a stapedial reflex (i.e., the electrical stapedius reflex threshold [eSRT]) can be measured to estimate the upper bound of stimulation on individual or a subset of CI electrodes. However, eSRTs measured for individual electrodes or a subset of electrodes cannot be used to predict the global adjustment of electrical stimulation levels needed to achieve comfortable loudness sensations that can be readily used in a speech coding strategy. In the present study, eSRTs were measured for 1-, 4-, and 15-electrode stimulation to (1) determine changes in eSRT levels as a function of the electrode stimulation mode and (2) determine which stimulation mode eSRT levels best approximate comfortable loudness levels from patients' clinical maps. METHODS: eSRTs were measured with the 3 different electrical stimulation configurations in 9 CI patients and compared with behaviorally measured, comfortable loudness levels or M-levels from patients' clinical maps. RESULTS: A linear, mixed-effects, repeated-measures analysis revealed significant differences (p < 0.01) between eSRTs measured as a function of the stimulation mode. No significant differences (p = 0.059) were measured between 15-electrode eSRTs and M-levels from patients' clinical maps. The eSRTs measured for 1- and 4-electrode stimulation differed significantly (p < 0.05) from the M-levels on the corresponding electrodes from the patients' clinical map. CONCLUSION: eSRT profiles based on 1- or 4-electrode stimulation can be used to determine comfortable loudness level on either individual or a subset of electrodes, and 15-electrode eSRT profiles can be used to determine the upper bound of electrical stimulation that can be used in a speech coding strategy.

Acoustic Reflexes in Aural Atresia Patients: Evidence of an Intact Efferent System?

OBJECTIVE: To record crossed acoustic reflex thresholds (xART's) postoperatively from patients after surgical repair of unilateral congenital aural atresia (CAA). To seek explanations for when xARTs can and cannot be recorded. We hope to understand the implications for this central auditory reflex despite early afferent deprivation. METHODS: Patients who underwent surgery to correct unilateral CAA at a tertiary academic medical were prospectively enrolled to evaluate for the presence of xART. Preoperative ARTs in the normal (non-atretic) ear, and postoperative ipsilateral ARTs (stimulus in the normal ear) and contralateral ARTs (stimulus in the newly reconstructed atretic ear; record in the normal ear) were measured at 500, 1000, and 2000 Hz. RESULTS: Four of 11 patients with normal ipsilateral reflex thresholds preoperatively demonstrated crossed acoustic reflexes postoperatively (stimulus in reconstructed ear; record from normal ear). Four other patients demonstrated normal ipsilateral thresholds preoperatively but did not have crossed reflexes postoperatively. No reflexes (pre- or postoperatively) could be recorded in 3 patients. Crossed reflex threshold is significantly correlated with the postoperative audiometric threshold. There was no correlation between ipsilateral and contralateral reflex thresholds. CONCLUSION: Crossed acoustic reflexes can be recorded from some but not all postoperative atresia patients, and the thresholds for those reflexes correlate with the postoperative pure tone threshold. The presence of acoustic reflexes implies an intact CN VIII-to-opposite CN VII central reflex arc despite early unilateral sound deprivation.

The effect of Valsalva and Jendrassik maneuvers on acoustic reflex / El efecto de las maniobras de Valsalva y Jendrassik sobre el reflejo acústico

AIMS: Studying modulation of acoustic reflex by the Valsalva and the Jendrassik manoeuvres. SETTINGS AND DESIGN: Quasi-experimental research with the pre-post testing design. METHODS AND MATERIAL: This self-control study was conducted on 12 healthy college students aged 21.23 ± 2.02 years. They were well trained to perform the standard Valsalva manoeuvre: maintenance of a 15-second expiratory pressure at 40 mmHg with open glottis. The Jendrassik manoeuver was performed by pulling clenched hands. Acoustic reflex threshold, acoustic reflex decay, middle ear pressure and compliance were measured before and after the Valsalva and the Jendrassik manoeuvres. The order of the right or the left ear recording was random. The recovery time following manoeuvres were 5 minutes. STATISTICAL ANALYSIS USED: All variables were compared using the repeated measured ANOVA. RESULTS: There were no statistical differences in the threshold and in the decay of acoustic reflex before and after the Valsalva and the Jendrassik manoeuvres. This finding was similar in both ears and had no laterality. CONCLUSIONS: The Valsalva and the Jendrassik manoeuvres as modulator of some somatic and autonomic reflexes including the sound induced startle reflex have no effect on acoustic reflex

OBJETIVOS: Estudiar la modulación del reflejo acústico mediante las maniobras de Valsalva y Jendrassik. CONFIGURIACIÓN Y DISEÑO: Investigación cuasi experimental con el diseño de prueba previa y posterior. MATERIALES Y MÉTODOS: Este estudio de autocontrol se realizó en 12 estudiantes universitarios sanos de 21.23 ± 2.02 años. Estaban bien entrenados para realizar la maniobra estándar de Valsalva: mantenimiento de una presión espiratoria de 15 segundos a 40 mmHg con una glotis abierta. La maniobra de Jendrassik se realizó tirando de las manos apretadas. El umbral del reflejo acústico, la disminución del reflejo acústico, la presión del oído medio y el cumplimiento se midieron antes y después de las maniobras de Valsalva y Jendrassik. El orden de la grabación del oído derecho o izquierdo fue aleatorio. El tiempo de recuperación después de las maniobras fue de 5 minutos. ANÁLISIS ESTADÍSTICO UTILIZADO: Todas las variables se compararon utilizando el ANOVA medido repetidamente. RESULTADOS: No hubo diferencias estadísticas en el umbral y en la decadencia del reflejo acústico antes y después de las maniobras de Valsalva y Jendrassik. Este hallazgo fue similar en ambos oídos y no tenía lateralidad. CONCLUSIONES: Las maniobras de Valsalva y Jendrassik como moduladores de algunos reflejos somáticos y autónomos, incluido el reflejo de sobresalto inducido por el sonido, no tienen efecto sobre el reflejo acústico

Long-term moderate noise exposure enhances the medial olivocochlear reflex.

OBJECTIVE: To investigate the effects of long-term moderate noise on hearing functions, MOCR, and MEMR. METHODS: Mice were exposed to the moderate noise (11.2 - 22.4 kHz, 80 dB SPL, 6 h/day, 4 weeks). Subsequently, the hearing functions, including threshold and input-output roles of ABR (auditory brainstem response) and cubic (2f1-f2) DPOAEs (distortion product otoacoustic emissions) were evaluated. Also, MEMR and MOCR were assessed shortly after or at four weeks following the termination of exposure to the noise. RESULTS: The mice's acoustic suppression reflex was strengthened, hearing functions and MEMR were unaffected four weeks after the moderate noise. For primary tones of 16, 20 and 24 kHz, the strengths of contralateral and ipsilateral suppression in the noise group were about double those recorded in the control group. In order to further determine whether the functional changes of the afferent or efferent nerves increased the strengths of acoustic suppression, the mouse's left ear was inserted the earplug, and then exposed the moderate noise for four weeks. The strengths of contralateral suppression at 16, 20 and 24 kHz were increased for the noise + earplug than for the control group and were indistinguishable between the noise + earplug and the noise group. While no significant changes were found in the strengths of ipsilateral suppression at all frequencies for the noise + earplug group compared with the control group. Under ketamine/xylazine anesthesia, the broadband suppressor noise did not stimulate the MEMR by 20 min post-induction at all frequencies in three groups. CONCLUSION: Our data demonstrated that the long-term moderate noise-exposure strengthened mice's MOCR by changing its afferent nerves, and unaffected cochlear hair cells and type I spiral ganglion neurons.

Typewriter tinnitus: An investigative comparison with middle ear myoclonic tinnitus and its long-term therapeutic response to carbamazepine.

OBJECTIVES: Due to its rarity and similar sound, typewriter tinnitus (TT) can be misdiagnosed as middle ear myoclonic tinnitus (MEMT). We aim to clarify the characteristics of TT compared to MEMT, and the long-term therapeutic response to carbamazepine. METHODS: Fourteen patients with TT and 28 patients with MEMT were enrolled. RESULTS: TT patients were older than MEMT patients, and their tinnitus symptoms were mostly unilateral. Tinnitus symptoms, which is associated with dizziness, facial spasm, and head motion, were more common in TT, whereas MEMT were more related to noise. Acoustic reflex decay perturbation and low loudness discomfort level were diagnostic signs in MEMT patients, while decreased level of wave II in ABR was the most reliable sign in TT patients. All TT patients exhibited partial or complete response to carbamazepine, but there was a relapse rate after withdrawal of the drug was 60%. Increase in age and longer duration of symptoms were the risk factors of relapse of TT. CONCLUSION: The different characteristics observed in this study will be helpful to diagnose TT and MENT. Duration of tinnitus was the most important long-term prognostic factor of the carbamazepine trial, which indicates the importance of its earlier diagnosis.

Auditory hyper-responsiveness in autism spectrum disorder, terminologies and physiological mechanisms involved: systematic review. / Hiper-responsividade auditiva no transtorno do espectro autista, terminologias e mecanismos fisiológicos envolvidos: revisão sistemática.

PURPOSE: this paper aims to identify the most used terminologies to designate the disproportional behavior to sounds in the autism spectrum disorder (ASD) and its relationship with the respective tools for its investigation, as well as its occurrence and outcomes. RESEARCH STRATEGIES: the databases used were PubMed, PsycINFO, Web of Science, Scielo and Lilacs. The keywords used were "autism", "hyperacusis" and "auditory perception", with the following combinations: "autism AND hyperacusis" and "autism AND auditory perception". SELECTION CRITERIA: individuals diagnosed with ASD of any age group; available abstract; papers in English, Spanish and Brazilian Portuguese; case series, prevalence and incidence studies, cohort and clinical trials. DATA ANALYSIS: we analyzed studies with individuals diagnosed with ASD of any age group; reference in the title and/or summary of the occurrence of disproportional behavior to sounds, accepting the terms hyper-responsiveness, hypersensitivity and hyperacusis; summary available; papers in English, Spanish and Brazilian Portuguese; series of cases, prevalence and incidence studies, cohort and clinical trials. RESULTS: Of the 692 studies resulting from the consultation, 13 studies could achieve the established requirements. CONCLUSION: The term auditory hypersensitivity was the most commonly used to designate disproportional behavior to sounds, followed by hyperacusis. There was no relationship between the terms and the respective research tool, and the questionnaires were the most used to designate the referred behavior, whose reported frequency was from 42.1% to 69.0%. The auditory behavior tests when performed showed the involvement of the auditory, afferent and efferent neural pathways.

OBJETIVO: identificar as terminologias mais utilizadas para designar o comportamento desproporcional a determinados sons (CDS) no TEA e sua relação com as respectivas ferramentas para sua investigação, assim como sua ocorrência e desfechos. ESTRATÉGIA DE PESQUISA: Foram utilizadas as bases de dados: PubMed, PsycINFO, Web of Science, Scielo e Lilacs. As palavras-chave utilizadas foram "autism", "hyperacusis" e "auditoryperception", com as seguintes combinações: "autism AND hyperacusis" e "autism AND auditoryperception". CRITÉRIOS DE SELEÇÃO: Foram incluídos os trabalhos com diagnóstico de TEA, de qualquer faixa etária; resumo disponível; Artigos em inglês, espanhol e português brasileiro; série de casos, estudos de prevalência e incidência, coorte e ensaios clínicos. ANÁLISE DOS DADOS: Foram analisados estudos com sujeitos com diagnóstico de TEA de qualquer faixa etária; referência no título e/ou resumo da ocorrência do CDS, aceitando os termos hiper-responsividade, hipersensibilidade e hiperacusia; resumo disponível; artigos em inglês, espanhol e português brasileiro; série de casos, estudos de prevalência e incidência, coorte e ensaios clínicos. RESULTADOS: Dos 692 estudos resultantes da consulta, foram identificados 13 que atendiam aos requisitos estabelecidos. CONCLUSÃO: O termo hipersensibilidade auditiva foi o mais empregado para designar o CDS, seguido da hiperacusia. Não houve relação entre os termos e a respectiva ferramenta de investigação, sendo os questionários os mais utilizados para designar o referido comportamento, cuja frequência relatada foi de 42,1% a 69,0%. Os testes auditivos, quando realizados, mostraram o envolvimento das vias neurais auditivas, aferente e eferente.

Dyna-CT of the temporal bone for case-specific three-dimensional rendering of the stapedial muscle for planning of electrically evoked stapedius reflex threshold determination during cochlear implantation directly from the stapedius muscle via a retrofacial approach: a pilot study.

PURPOSE: Evaluation of 3D Dyna-CTs to improve cochlear implantation (CI) planning and intraoperative electrically elicited stapedius reflex threshold (ESRT) measurements. METHODS: A prospective observational cohort study was performed. Anonymized data collection of Dyna-CTs and CI surgeries in which a retrofacial approach was implemented to access the stapedius muscle. 3D Dyna-CTs of 30 patients and the intraoperative confirmation of the predication in 5/30 patients during CI surgery were evaluated. Inter-rater reliability was also analyzed along with the predictive value of this evaluation. RESULTS: 36 representative structures of the middle and inner ear and 3D renderings of the Dyna-CTs were evaluated by four otoneurological surgeons. Fleiss' kappa values for the evaluation of the visibility were high (> 0.7) for most of the anatomical structures. The stapedius muscle was visible in 90% of the cases. Using the 3D data, the retrofacial access to the stapedius muscles was estimated as feasible in 86.7%. Fleiss' kappa value of the evaluation of the accessibility was 0.942. The intraoperative exploration of the stapedius muscle confirmed the preoperative prediction in all five selected patients (four patients with predicted accessibility and one patient with predicted inaccessibility). CONCLUSIONS: The use of Dyna-CT and 3D rendering is a helpful tool for preoperative planning of cochlear implantations and ESRT measurements from the stapedius muscle via the retrofacial approach.

Establishing critical differences in ear-canal stimulus amplitude for detecting middle ear muscle reflex activation during olivocochlear efferent measurements.

Objective: Assessments of the medial olivocochlear reflex (MOCR) may have clinical utility. The MOCR is measured using contralateral inhibition of otoacoustic emissions but concurrent activation of the middle ear muscle reflex (MEMR) confounds test interpretation. MEMR activation can be detected using the change in ear-canal stimulus amplitude without versus with an MOCR elicitor. This study provides a description of how critical differences in ear-canal stimulus amplitude can be established.Design: Clicks were presented in right ears without and with a contralateral MOCR elicitor. Ear-canal stimulus amplitudes were measured. Two measurements without an elicitor were used to develop critical differences. MEMR activation was considered present if the difference in ear-canal stimulus amplitude without versus with an elicitor exceeded the critical difference.Study sample: Forty-six normal-hearing adults (mean age = 23.4 years, 35 females) participated, with data from 44 participants included in the final analysis.Results: Two participants exceeded the 95% critical difference. The 80, 90 and 99% critical differences are also reported for reference.Conclusions: Results suggest that the contralateral elicitor can evoke the MEMR in a small number of participants. The methods described in this paper can be used for developing equipment- and clinic-specific critical differences for detecting MEMR activation.

A influência das curvas timpanométricas nos resultados das emissões otoacústicas / The influence of tympanometric curves on the results of otoacoustic emissions

RESUMO Objetivo Analisar as emissões otoacústicas evocadas produto de distorção (EOAPD) de indivíduos adultos entre 18 e 50 anos, com audição normal, e associar os resultados com os achados à timpanometria. Métodos Foram selecionados 27 prontuários de adultos com audição dentro dos padrões de normalidade, sem queixa auditiva, com curva timpanométrica do tipo A, Ad ou Ar, presença de reflexos acústicos, sem queixa de zumbido e de exposição frequente a níveis de pressão sonora elevados, com repouso auditivo mínimo de 14 horas no momento do exame e que realizaram o exame de emissões otoacústicas evocadas produto de distorção. Os resultados do exame de emissões otoacústicas foram analisados considerando os resultados das curvas timpanométricas apresentadas por estes indivíduos. Para análise dos dados foram aplicados testes não paramétricos e o nível de significância foi de 5%. Resultados foram analisados os resultados das emissões otoacústicas de 54 orelhas. Observou-se maior ocorrência da curva do tipo A em indivíduos sem queixas auditivas. Independente do lado, a maioria das orelhas que apresentou resposta presente ao exame de EOAPD, apresentou, também, curva timpanométrica normal. Observou-se correlação positiva entre a amplitude das EOAPD e o volume da orelha média para as frequências de 6000 Hz e uma tendência à significância em 4000 Hz Conclusão Foi possível concluir que há maior ocorrência de emissões otoacústicas presentes em indivíduos com audição normal e curva timpanométrica do tipo A e que a amplitude das EOAPD em 6000 Hz mostra-se menor nos indivíduos com audição normal e curva timpanométrica do tipo Ar ou Ad.

ABSTRACT Purpose To analyze distortion product evoked otoacoustic emissions in normal-hearing adults aged between 18 and 50 years old, and to associate the results with the findings of tympanometry. Methods 27 medical records were selected of adults with the following conditions: normal hearing; without auditory complaint; with type A, Ad or Ar tympanometric curve; with presence of acoustic reflexes; with no complaint of tinnitus or frequent exposure to high sound pressure levels; with minimal auditory rest of 14 hours at the time of the test, and who had undergone distortion product evoked otoacoustic emission (DPOAE) testing. The results of otoacoustic emissions were analyzed considering the results of the tympanometric curves presented by these individuals. For the data analysis, non-parametric tests were applied, and the level of significance was 5%. Results The results of otoacoustic emissions of 54 ears were analyzed. There was a greater occurrence of the type A curve in individuals without auditory complaints. Regardless of side, most ears whose response was present in the DPOAE test also presented normal tympanometric curve. There was a positive correlation between DPOAE amplitude and middle ear volume for the 6000Hz frequencies (p = 0.048) and a tendency to significance at 4000Hz (p = 0.054). Conclusion There was a higher occurrence of otoacoustic emissions present in normal-hearing individuals and type A tympanometric curve, and the amplitude of DPOAE at 6000Hz was smaller in normal-hearing individuals and type Ar or Ad tympanometric curve.

Hiper-responsividade auditiva no transtorno do espectro autista, terminologias e mecanismos fisiológicos envolvidos: revisão sistemática / Auditory hyper-responsiveness in autism spectrum disorder, terminologies and physiological mechanisms involved: systematic review

RESUMO Objetivo identificar as terminologias mais utilizadas para designar o comportamento desproporcional a determinados sons (CDS) no TEA e sua relação com as respectivas ferramentas para sua investigação, assim como sua ocorrência e desfechos. Estratégia de pesquisa Foram utilizadas as bases de dados: PubMed, PsycINFO, Web of Science, Scielo e Lilacs. As palavras-chave utilizadas foram "autism", "hyperacusis" e "auditoryperception", com as seguintes combinações: "autism AND hyperacusis" e "autism AND auditoryperception". Critérios de seleção Foram incluídos os trabalhos com diagnóstico de TEA, de qualquer faixa etária; resumo disponível; Artigos em inglês, espanhol e português brasileiro; série de casos, estudos de prevalência e incidência, coorte e ensaios clínicos. Análise dos dados Foram analisados estudos com sujeitos com diagnóstico de TEA de qualquer faixa etária; referência no título e/ou resumo da ocorrência do CDS, aceitando os termos hiper-responsividade, hipersensibilidade e hiperacusia; resumo disponível; artigos em inglês, espanhol e português brasileiro; série de casos, estudos de prevalência e incidência, coorte e ensaios clínicos. Resultados Dos 692 estudos resultantes da consulta, foram identificados 13 que atendiam aos requisitos estabelecidos. Conclusão O termo hipersensibilidade auditiva foi o mais empregado para designar o CDS, seguido da hiperacusia. Não houve relação entre os termos e a respectiva ferramenta de investigação, sendo os questionários os mais utilizados para designar o referido comportamento, cuja frequência relatada foi de 42,1% a 69,0%. Os testes auditivos, quando realizados, mostraram o envolvimento das vias neurais auditivas, aferente e eferente.

ABSTRACT Purpose this paper aims to identify the most used terminologies to designate the disproportional behavior to sounds in the autism spectrum disorder (ASD) and its relationship with the respective tools for its investigation, as well as its occurrence and outcomes. Research strategies the databases used were PubMed, PsycINFO, Web of Science, Scielo and Lilacs. The keywords used were "autism", "hyperacusis" and "auditory perception", with the following combinations: "autism AND hyperacusis" and "autism AND auditory perception". Selection criteria individuals diagnosed with ASD of any age group; available abstract; papers in English, Spanish and Brazilian Portuguese; case series, prevalence and incidence studies, cohort and clinical trials. Data analysis we analyzed studies with individuals diagnosed with ASD of any age group; reference in the title and/or summary of the occurrence of disproportional behavior to sounds, accepting the terms hyper-responsiveness, hypersensitivity and hyperacusis; summary available; papers in English, Spanish and Brazilian Portuguese; series of cases, prevalence and incidence studies, cohort and clinical trials. Results Of the 692 studies resulting from the consultation, 13 studies could achieve the established requirements. Conclusion The term auditory hypersensitivity was the most commonly used to designate disproportional behavior to sounds, followed by hyperacusis. There was no relationship between the terms and the respective research tool, and the questionnaires were the most used to designate the referred behavior, whose reported frequency was from 42.1% to 69.0%. The auditory behavior tests when performed showed the involvement of the auditory, afferent and efferent neural pathways.

No Effect of Interstimulus Interval on Acoustic Reflex Thresholds.

The acoustic reflex (AR), a longstanding component of the audiological test battery, has received renewed attention in the context of noise-induced cochlear synaptopathy-the destruction of synapses between inner hair cells and auditory nerve fibers. Noninvasive proxy measures of synaptopathy are widely sought, and AR thresholds (ARTs) correlate closely with synaptic survival in rodents. However, measurement in humans at high stimulus frequencies-likely important when testing for noise-induced pathology-can be challenging; reflexes at 4 kHz are frequently absent or occur only at high stimulus levels, even in young people with clinically normal audiograms. This phenomenon may partly reflect differences across stimulus frequency in the temporal characteristics of the response; later onset of the response, earlier onset of adaptation, and higher rate of adaptation have been observed at 4 kHz than at 1 kHz. One temporal aspect of the response that has received little attention is the interstimulus interval (ISI); inadequate duration of ISI might lead to incomplete recovery of the response between successive presentations and consequent response fatigue. This research aimed to test for effects of ISI on ARTs in normally hearing young humans, measured at 1 and 4 kHz. Contrary to our hypotheses, increasing ISIs from 2.5 to 8.5 s did not reduce ART level, nor raise ART reliability. Results confirm that clinically measured ARTs-including those at 4 kHz-can exhibit excellent reliability and that relatively short (2.5 s) ISIs are adequate for the measurement of sensitive and reliable ARTs.

Vestibulo masseteric reflex and acoustic masseteric Reflex. Normative data and effects of age and gender.

OBJECTIVE: To provide normative data for the Vestibulo-Masseteric Reflex (VMR) and Acoustic-Masseteric Reflex (AMR) in healthy subjects, stratified for age and gender. METHODS: A total of 82 healthy subjects (M:F 43:39, mean age 39.3 ±â€¯18.4 years, range 13-79 years) underwent recording of click-evoked VMR and AMR (0.1 ms duration, 5 Hz frequency) from active masseter muscles. Masseter responses to uni- and bilateral stimulation were recorded in a zygomatic and a mandibular configuration, according to the position of the reference electrode. Stimulation intensity curves were recorded for each reflex in ten subjects (mean age 20.7 ±â€¯8.1 years). Gender effect was investigated in 62 subjects and age effect was analyzed in six 10-subject groups aged from <25 to >65 years. Onset and peak latencies, interpeak intervals, raw and corrected amplitudes, latency and amplitude asymmetries were analyzed. RESULTS: VMR had a higher elicitation rate than AMR. For both reflexes, rates of elicitation, and corrected amplitudes were higher in the zygomatic configuration, and bilateral stimulation elicited larger responses. Best acoustic ranges of elicitation were 98-113 dB for AMR and 128-138 dB for VMR. Reflex latencies were shorter in females than males. Frequency and amplitude of VMR and AMR decreased substantially over 55 year olds. CONCLUSIONS: VMR and AMR can be easily performed in any clinical neurophysiology laboratory. SIGNIFICANCE: These reflexes can find application in the investigation of brainstem function in central neurological disorders.

Auditory brainstem function in women with vestibular migraine: a controlled study.

BACKGROUND: Vestibular migraine (VM) has been recognized as a diagnostic entity over the past three decades. It affects up to 1% of the general population and 7% of patients seen in dizziness clinics. It is still underdiagnosed; consequently, it is important to conduct clinical studies that address diagnostic indicators of VM. The aim of this study was to assess auditory brainstem function in women with vestibular migraine using electrophysiological testing, contralateral acoustic reflex and loudness discomfort level. METHODS: The study group consisted of 29 women with vestibular migraine in the interictal period, and the control group comprised 25 healthy women. Auditory brainstem response, frequency following response, binaural interaction component and assessment of contralateral efferent suppression were performed. The threshold of loudness discomfort and the contralateral acoustic reflex were also investigated. The results were compared between the groups. RESULTS: There was a statistically significant difference between the groups in the frequency following response and the loudness discomfort level. CONCLUSIONS: The current study suggested that temporal auditory processing and loudness discomfort levels are altered in VM patients during the interictal period, indicating that these measures may be useful as diagnostic criteria.

Lateralization of virtual sound sources with a binaural cochlear-implant sound coding strategy inspired by the medial olivocochlear reflex.

Many users of bilateral cochlear implants (BiCIs) localize sound sources less accurately than do people with normal hearing. This may be partly due to using two independently functioning CIs with fixed compression, which distorts and/or reduces interaural level differences (ILDs). Here, we investigate the potential benefits of using binaurally coupled, dynamic compression inspired by the medial olivocochlear reflex; an approach termed "the MOC strategy" (Lopez-Poveda et al., 2016, Ear Hear 37:e138-e148). Twelve BiCI users were asked to localize wideband (125-6000 Hz) noise tokens in a virtual horizontal plane. Stimuli were processed through a standard (STD) sound processing strategy (i.e., involving two independently functioning sound processors with fixed compression) and three different implementations of the MOC strategy: one with fast (MOC1) and two with slower contralateral control of compression (MOC2 and MOC3). The MOC1 and MOC2 strategies had effectively greater inhibition in the higher than in the lower frequency channels, while the MOC3 strategy had slightly greater inhibition in the lower than in the higher frequency channels. Localization was most accurate with the MOC1 strategy, presumably because it provided the largest and less ambiguous ILDs. The angle error improved slightly from 25.3° with the STD strategy to 22.7° with the MOC1 strategy. The improvement in localization ability over the STD strategy disappeared when the contralateral control of compression was made slower, presumably because stimuli were too short (200 ms) for the slower contralateral inhibition to enhance ILDs. Results suggest that some MOC implementations hold promise for improving not only speech-in-noise intelligibility, as shown elsewhere, but also sound source lateralization.