Audiometría de altas frecuencias en adolescentes expuestos a ruidos / High frequency audiometry in adolescents exposed to noises

Introducción: La audiometría de altas frecuencias (9000-20 000 Hz) puede ser de gran utilidad en el diagnóstico precoz de hipoacusia inducida por ruidos en contraste con la audiometría convencional (125-8000 Hz). Objetivo: Evaluar la utilidad de la audiometría de altas frecuencias en el diagnóstico precoz de la hipoacusia inducida por ruidos en adolescentes. Métodos: Estudio descriptivo, observacional y transversal en 85 adolescentes expuestos a ruidos; 45 cursaban el décimo grado en un preuniversitario de la provincia La Habana, en el curso escolar 2013-2014 y 40, el primer año de la carrera de medicina, en una facultad de La Habana en el curso escolar 2015- 2016. A todos se le realizó una encuesta, examen físico de otorrinolaringología, audiometría convencional y audiometría de alta frecuencia. Resultados: La audiometría convencional fue normal en todos los casos. En la audiometría de altas frecuencias en todos los adolescentes estudiados comenzó a disminuir la audición a partir de los 13 000 Hz y se apreció una hipoacusia neurosensorial en aumento hasta 85 decibeles en oído derecho y 78 decibeles en oído izquierdo en 20 000 Hz de frecuencia. Conclusiones: Los adolescentes evaluados tienen hábitos auditivos que pueden perjudicar su audición, todos ya poseen signos de daño que no se manifiestan a través de la audiometría convencional pero sí a través de la audiometría de alta frecuencia en las diferentes exposiciones a ruidos de altos decibeles. Lo anterior demuestra la utilidad de esta audiometría, no solo dentro del campo de la audiología, sino también en la medicina preventiva(AU)

Introduction: High frequency audiometry (9000-20 000 Hz) can be really useful in the early diagnosis of deafness induced by noises, in contrast with conventional tonal audiometry (125-8000 Hz). Objective: Assess the usefulness of high frequency audiometry in the early diagnosis of deafness induced by noises in adolescents. Methods: Descriptive, observational and cross-sectional study in 85 adolescents exposed to noises; 45 of them were studying the 10th grade in a high school of Havana province, and 40 of them were in the first year of Medicine in a faculty of Havana province during school year 2015-2016. All of them took a survey, a physical examination of otolaryngology, liminar total audiometry and high frequency audiometry. Results: Tonal audiometry was normal in all the cases. In high frequency audiometry of all the studied adolescents started to decrease audition from 13000 HZ and it was noticed an increasing neurosensorial deafness up to 85 decibels in the right ear and 78 decibels in the left ear in 20 000 Hz of frequency. Conclusions: The adolescents assessed have auditive habits that can jeopardize their audition; all of them already have signs of damage that are not noticed in the tonal audiometry but in the high frequency audiometry in the different exposures to noises of high decibels. This proves the usefulness of this kind of audiometry not only in the field of audiology, but also in preventive medicine(AU)

Auditory steady-state response in cochlear implant patients / Potenciales evocados auditivos de estado estable en pacientes con implante coclear

INTRODUCTION AND OBJECTIVE: Auditory steady state responses to continuous amplitude modulated tones at rates between 70 and 110 Hz, have been proposed as a feasible alternative to objective frequency specific audiometry in cochlear implant subjects. The aim of the present study is to obtain physiological thresholds by means of auditory steady-state response in cochlear implant patients (Clarion HiRes 90 K), with acoustic stimulation, on free field conditions and to verify its biological origin. METHODS: 11 subjects comprised the sample. Four amplitude modulated tones of 500, 1000, 2000 and 4000 Hz were used as stimuli, using the multiple frequency technique. The recording of auditory steady-state response was also recorded at 0 dB HL of intensity, non-specific stimulus and using a masking technique. RESULTS: The study enabled the electrophysiological thresholds to be obtained for each subject of the explored sample. There were no auditory steady-state responses at either 0dB or non-specific stimulus recordings. It was possible to obtain the masking thresholds. A difference was identified between behavioral and electrophysiological thresholds of -6 ± 16, -2 ± 13, 0 ± 22 and -8 ± 18 dB at frequencies of 500, 1000, 2000 and 4000 Hz respectively. CONCLUSIONS: The auditory steady state response seems to be a suitable technique to evaluate the hearing threshold in cochlear implant subjects

INTRODUCCIÓN Y OBJETIVOS: Los potenciales evocados auditivos de estado estable (PEAEE) por estimulación con tonos modulados en amplitud entre 70 y 110 Hz han sido propuestos como una alternativa factible para realizar una audiometría objetiva en pacientes con implante coclear. El objetivo del presente estudio es verificar el origen biológico de los umbrales auditivos obtenidos mediante PEAEE por estimulación acústica y en condiciones de campo libre, en pacientes con implante coclear (Clarion HiRes 90 K). MÉTODOS: La muestra constó de 11 pacientes. Cuatro tonos modulados en amplitud con frecuencias portadoras de 500, 1.000, 2.000 y 4.000 Hz y presentados simultáneamente fueron empleados como estímulo. Se registraron series de intensidad hasta alcanzar el umbral auditivo, así como registros a 0 dB HL, con estímulos no específicos y empleando técnicas de enmascaramiento. RESULTADOS: El estudio permitió obtener los umbrales electrofisiológicos par cada paciente de la muestra explorada. No hubo respuesta de estado estable ni a 0dB ni al emplear estímulos no específicos. Fue posible obtener los umbrales de enmascaramiento. Se identificó una diferencia entre los umbrales conductuales y electrofisiológicos de -6 ± 16dB, -2 ± 13dB, 0 ± 22dB y -8 ± 18dB a las frecuencias de 500, 1.000, 2.000 y 4.000 Hz, respectivamente. CONCLUSIONES: Los PEAEE pueden constituir una técnica apropiada para evaluar el umbral auditivo en sujetos con implante coclear

Auditory steady-state response in cochlear implant patients.

INTRODUCTION AND OBJECTIVE: Auditory steady state responses to continuous amplitude modulated tones at rates between 70 and 110Hz, have been proposed as a feasible alternative to objective frequency specific audiometry in cochlear implant subjects. The aim of the present study is to obtain physiological thresholds by means of auditory steady-state response in cochlear implant patients (Clarion HiRes 90K), with acoustic stimulation, on free field conditions and to verify its biological origin. METHODS: 11 subjects comprised the sample. Four amplitude modulated tones of 500, 1000, 2000 and 4000Hz were used as stimuli, using the multiple frequency technique. The recording of auditory steady-state response was also recorded at 0dB HL of intensity, non-specific stimulus and using a masking technique. RESULTS: The study enabled the electrophysiological thresholds to be obtained for each subject of the explored sample. There were no auditory steady-state responses at either 0dB or non-specific stimulus recordings. It was possible to obtain the masking thresholds. A difference was identified between behavioral and electrophysiological thresholds of -6±16, -2±13, 0±22 and -8±18dB at frequencies of 500, 1000, 2000 and 4000Hz respectively. CONCLUSIONS: The auditory steady state response seems to be a suitable technique to evaluate the hearing threshold in cochlear implant subjects.

Audiometría de altas frecuencias: utilidad en el diagnóstico audiológico de la hipoacusia inducida por ruidos / Audiometry of high frequencies: usefulness in the audiological diagnosis of hearing-induced hearing loss

Fundamento: la disponibilidad de reproductores de audio ha aumentado y potenciado la exposición a ruidos intensos por periodos prolongados. Este ruido recreacional resultado de las actividades de esparcimiento, como el uso de reproductores de música, asistencia a conciertos, discotecas, es un factor de riesgo para presentar deterioro auditivo; donde la hipoacusia inducida por el ruido es una de las principales causas de discapacidad prevenible. Objetivo: determinar la utilidad de la audiometría de altas frecuencias, para la predicción de hipoacusias inducidas por ruidos. Métodos: se realizó un estudio observacional, analítico, transversal, con encuesta, examen físico de Otorrinolaringología, audiometría tonal liminar y audiometría de altas frecuencias desde septiembre de 2013 hasta junio 2016 a 80 adolescentes de la provincia La Habana para describir la incidencia de las hipoacusias inducidas por ruido y su relación con los factores que las producen. Resultados: la audiometría tonal realizada a los 80 adolescentes fue normal y la audiometría de altas frecuencias comenzó a disminuir la audición a partir de 13 000 Hz donde se observó una hipoacusia neurosensorial en aumento hasta 90 dB en 20 000 Hz de frecuencia. Todos los adolescentes estudiados usan reproductores de música personal más de dos horas diarias. Conclusiones: considerar la audiometría de alta frecuencia como un método diagnóstico para la detección temprana de trastornos de audición en pacientes con riesgo específico como la exposición a ruidos, con el fin de que se convierta en una herramienta habitual en la exploración audiológica.

Background: the availability of audio players has increased and has boosted exposure to loud noises for extended periods. This recreational noise resulting from recreational activities, such as the use of music players, concert attendance, discotheques, is a risk factor for hearing impairment; being hearing-induced hearing loss one of the main causes of preventable disability. Objective: The aim of this study was to determine the usefulness of high frequency audiometry for the prediction of noise-induced hearing loss. Methods: an observational, analytical, cross-sectional study, with a survey, physical examination of Otorhinolaryngology, pure tone audiometry and high frequency audiometry were performed from September 2013 to June 2016 in 80 teenagers from Havana to describe the incidence of hypoacusis induced by noise and its relation with the factors that produce it. Results: tonal audiometry performed in 80 teenagers was normal and high frequency audiometry began to decrease hearing from 13 000 Hz, observing an increase in neurosensorial hearing loss up to 90 dB at 20 000 Hz frequency. All teenagers studied used personal music players more than two hours a day. Conclusions: considering high frequency audiometry as a diagnostic method for the early detection of hearing disorders in patients with specific risk such as exposure to noise, in order to become a common tool in audiological exploration.

Audiometría de altas frecuencias: utilidad en el diagnóstico audiológico de la hipoacusia inducida por ruidos / Audiometry of high frequencies: usefulness in the audiological diagnosis of hearing-induced hearing loss

Fundamento: la disponibilidad de reproductores de audio ha aumentado y potenciado la exposición a ruidos intensos por periodos prolongados. Este ruido recreacional resultado de las actividades de esparcimiento, como el uso de reproductores de música, asistencia a conciertos, discotecas, es un factor de riesgo para presentar deterioro auditivo; donde la hipoacusia inducida por el ruido es una de las principales causas de discapacidad prevenible.Objetivo: determinar la utilidad de la audiometría de altas frecuencias, para la predicción de hipoacusias inducidas por ruidos.Métodos: se realizó un estudio observacional, analítico, transversal, con encuesta, examen físico de Otorrinolaringología, audiometría tonal liminar y audiometría de altas frecuencias desde septiembre de 2013 hasta junio 2016 a 80 adolescentes de la provincia La Habana para describir la incidencia de las hipoacusias inducidas por ruido y su relación con los factores que las producen.Resultados: la audiometría tonal realizada a los 80 adolescentes fue normal y la audiometría de altas frecuencias comenzó a disminuir la audición a partir de 13 000 Hz donde se observó una hipoacusia neurosensorial en aumento hasta 90 dB en 20 000 Hz de frecuencia. Todos los adolescentes estudiados usan reproductores de música personal más de dos horas diarias.Conclusiones: considerar la audiometría de alta frecuencia como un método diagnóstico para la detección temprana de trastornos de audición en pacientes con riesgo específico como la exposición a ruidos, con el fin de que se convierta en una herramienta habitual en la exploración audiológica(AU)

Background: the availability of audio players has increased and has boosted exposure to loud noises for extended periods. This recreational noise resulting from recreational activities, such as the use of music players, concert attendance, discotheques, is a risk factor for hearing impairment; being hearing-induced hearing loss one of the main causes of preventable disability.Objective: The aim of this study was to determine the usefulness of high frequency audiometry for the prediction of noise-induced hearing loss.Methods: an observational, analytical, cross-sectional study, with a survey, physical examination of Otorhinolaryngology, pure tone audiometry and high frequency audiometry were performed from September 2013 to June 2016 in 80 teenagers from Havana to describe the incidence of hypoacusis induced by noise and its relation with the factors that produce it.Results: tonal audiometry performed in 80 teenagers was normal and high frequency audiometry began to decrease hearing from 13 000 Hz, observing an increase in neurosensorial hearing loss up to 90 dB at 20 000 Hz frequency. All teenagers studied used personal music players more than two hours a day.Conclusions: considering high frequency audiometry as a diagnostic method for the early detection of hearing disorders in patients with specific risk such as exposure to noise, in order to become a common tool in audiological exploration(AU)

Implante coclear en niños con hipoacusia de causa genética por Síndrome Waardenburg y mutación 35delG / Effect of cochlear implant in children suffering genetic hypoacusis caused by Waardenburg Syndrome and 35delG mutation

Introducción: La hipoacusia neurosensorial es la forma más común de déficit auditivo, se calcula que más de 80 por ciento de todas las pérdidas auditivas congénitas son de origen genético, siendo estas distinguidas en sindrómicas y no sindrómicas; la mutación 35delG es la causa más frecuente de las primeras y el Síndrome Waardenburg (SW) es uno de los más frecuentes en las últimas, en ambas suelen identificarse pacientes con hipoacusias de severas a profundas (HSP). El implante coclear se considera una solución eficaz cuando la HSP no obtiene suficiente beneficio mediante prótesis auditivas.Objetivo: Analizar el resultado alcanzado con el uso del implante coclear en pacientes con HSP por SW y mutación 35delG. Material y Métodos: Se realizó un estudio descriptivo transversal. Fueron estudiados pacientes con HSP de causa genética, 27 debido a la mutación 35delG y 15 por SW. Se realizaron pruebas audiológicas y logofoniátricas. Resultados: La lesión que ocurre en el oído interno en los pacientes estudiados no parece afectar los beneficios que ofrece el implante coclear, si se dan las condiciones generales adecuadas. Conclusiones: El implante coclear es una alternativa terapéutica válida para la discapacidad auditiva debido a estas dos afecciones estudiadas; sin embargo, los que presentaron la mutación 35delG, alcanzaron mejores categorías de rendimiento auditivo(AU)

Introduction: Sensorineural hypoacusia is the most common form of hearing impairment, it is estimated that over 80 percent of all congenital hearing losses are from genetic origin, being distinguished in syndromic and non-syndromic; 35delG mutation is the most common cause of the first and Waardenburg syndrome (WS) is one of the most frequent in the last one; in both of them cases are usually identified patients with severe to profound hearing losses (HSP). The cochlear implant is considered an effective solution when the HSP do not get enough benefit through hearing aids. Objective: To analyze the results achieved with the use of cochlear implant in patients with HSP due to WS and 35delGmutation. Material and Methods: A descriptive cross-sectional study. Were studied patients with HSP of genetic cause, 27 due to 35delGmutation and 15 by WS. Hearing and logophoniatrics tests were performed.Results: Inner ear lesions happening in the in the studied patients it seems not affect the benefits of cochlear implant if general proper conditions are given.Conclusions: Cochlear Implant is a worthful therapeutic alternative for the hearing impaired due to these two studied illness; however, those with 35delG mutation, achieved best hearing performance categories(AU)

Comparing auditory steady-state responses amplitude evoked by simultaneous air- and bone-conducted stimulation in newborns.

OBJECTIVE: The aim of this study was to evaluate the potential interactions of the simultaneous presentation of air- and bone-conducted stimuli on auditory steady-state responses (ASSR) amplitude in newborns. DESIGN: Bone- and air-conducted stimuli were sinusoidal carrier tones of 500 and 2000 Hz respectively modulated in amplitude (95% depth). Air- and bone- conducted stimuli were either simultaneously recorded in the same ear using insert earphones and bone vibrator respectively, or recorded individually (single stimulation). STUDY SAMPLE: Sixty-nine well babies (135 ears) with ages ranging from 1 to 16 days (mean of 9.2 ± 7.9 days) were tested in this study. RESULTS: No significant changes in ASSR amplitude by air-conducted stimuli were observed when evoked by simultaneous or single stimulation. The same trend prevailed for ASSR amplitudes evoked by bone-conducted stimuli. CONCLUSIONS: The results of this study suggest that the simultaneous stimulation of air-and bone-conducted stimuli does not alter ASSR amplitude values in well babies. Therefore, the results support the use of this technique as a potential hearing screening tool to discriminate between conductive and sensorineural hearing loss.

Déficit en el procesamiento auditivo subcortical en pacientes esquizofrénicos. Revisión sobre posibles biomarcadores neurofisiológicos / Subcortical auditory processing deficit in schizophrenia. A review of potential neurophysiological biomarkers

La esquizofrenia es un trastorno mental crónico que afecta aproximadamente al 1% de la población mundial. Diagnosticar este trastorno se puede tornar difícil debido a que los criterios diagnósticos son complejos y sus síntomas se pueden presentar en una gran variedad de formas. Por lo tanto, se hace necesario contar con herramientas que ayuden a los médicos en su esfuerzo por diagnosticar este trastorno rápida y objetivamente. Algunos estudios han mostrado que estos pacientes podrían procesar los estímulos acústicos de una manera alterada a nivel subcortical. Sin embargo, a pesar de la abundante evidencia neurofisiológica sobre esta disfunción, los resultados aún son equívocos. En este trabajo se realiza una revisión exhaustiva de la literatura donde se abordan los resultados de los diferentes estudios neurofisiológicos publicados sobre el tema, así como las posibles causas de sus diferencias. Y por último, se analizan futuras técnicas, así como el impacto que tendrían en la práctica clínica en caso de ser validadas (AU)

Schizophrenia is a chronic mental disorder affecting approximately 1% of the population. It may sometimes be difficult to diagnose because the diagnostic criteria are complex and the symptoms may present themselves in a wide variety of manners in clinical practice. Therefore, there is a great need for a valid and reliable diagnostic tool to aid clinicians in arriving at the diagnoses in a timely and accurate manner. Previous studies have suggested that patients suffering from schizophrenia may process certain sound stimuli in the brainstem in an unusual manner. However, despite the abundant neurophysiological evidence of auditory system dysfunction, results are still equivocal. In this review, previously published neurophysiological findings in this field are analysed, as well as the possible causes for discrepancies. Finally, future techniques and the impact they could have on clinical practice, if validated, are also analysed (AU)

Cribado auditivo mediante potenciales evocados auditivos de estado estable obtenidos por estimulación simultánea de la vía aérea y la ósea / Hearing screening using auditory steady state responses obtained by simultaneous air- and bone-conduction stimuli

Introducción y objetivos: Minimizar los falsos positivos constituye un objetivo de los programas de cribado auditivo universal. Una manera de lograrlo sería diferenciar entre los trastornos neurosensoriales (verdaderos positivos) y los conductivos transitorios (falsos positivos) mediante un método que permita estudiar la respuesta del sistema auditivo ante la estimulación tanto por vía aérea como por vía ósea. El objetivo de este trabajo es evaluar la eficiencia diagnóstica de una prueba automatizada de cribado basada en el registro de potenciales evocados auditivos de estado estable obtenidos por estimulación simultánea de vía aérea y vía ósea. Métodos: Se estudiaron 80 bebés menores de 2 meses de edad. A todos se les realizó la prueba de cribado, siendo posteriormente citados para el estudio confirmatorio, cuyo resultado se consideró como criterio de verdad del estado audiológico del bebé. Resultados: Con esta prueba se obtuvo una eficiencia diagnóstica equivalente (un 100% de sensibilidad y un 97,7% de especificidad) a la reportada para otras pruebas utilizadas en el cribado (emisiones otoacústicas y potenciales evocados de tronco cerebral), con la ventaja adicional de que la introducción de la vía ósea en el cribado permitió reducir la cifra de falsos positivos del 13,3 al 2,2%. La duración de la prueba fue de 5,3 (± 1,9) min, siendo suficiente en el 34% de los casos una sola repetición para llegar al resultado. Conclusiones: Esta prueba automatizada de cribado basada en el registro de potenciales evocados auditivos de estado estable permitió discriminar entre los trastornos conductivos transitorios y los neurosensoriales, reduciendo así los falsos positivos y elevando la eficiencia diagnóstica de esta metodología (AU)

Introduction and objectives: Minimising false positives rates is an important goal of universal newborn hearing screening programmes. An adequate way for reaching that goal could be differentiating between transient conductive hearing losses (false positives) and permanent sensorineural hearing impairments (true positives) by means of a methodology that studies electrophysiological responses obtained using both air- and bone-conduction stimuli. Our objective was to evaluate the efficiency of an automated hearing screening test based on auditory steady state responses obtained using simultaneous air- and bone-conduction stimuli. Methods: A sample of 80 high risk babies lees than 2 months of born were screened using the automatic screening test. A confirmatory clinical and electrophysiological evaluation was used as the gold standard. Results: The estimated diagnostic efficiency of this screening test was equivalent (100% sensitivity and 97.7% specificity) to the efficiency reported for otoacoustic emissions and automated auditory brainstem responses. The introduction of bone conduction in the screening reduced the false positive rate from 13.3% to 2.2%. The test duration was 5.3 (± 1.9) min. In 34% of babies only one repetition of the test was needed to raising the result. Conclusions: The screening test performed quite well in this initial clinical trial, differentiating transient conductive hearing losses from permanent neurosensory impairments and improving the diagnostic efficiency of auditory steady state responses (AU)

Hearing screening using auditory steady state responses obtained by simultaneous air- and bone-conduction stimuli.

INTRODUCTION AND OBJECTIVES: Minimising false positives rates is an important goal of universal newborn hearing screening programmes. An adequate way for reaching that goal could be differentiating between transient conductive hearing losses (false positives) and permanent sensorineural hearing impairments (true positives) by means of a methodology that studies electrophysiological responses obtained using both air- and bone-conduction stimuli. Our objective was to evaluate the efficiency of an automated hearing screening test based on auditory steady state responses obtained using simultaneous air- and bone-conduction stimuli. METHODS: A sample of 80 high risk babies lees than 2 months of born were screened using the automatic screening test. A confirmatory clinical and electrophysiological evaluation was used as the gold standard. RESULTS: The estimated diagnostic efficiency of this screening test was equivalent (100% sensitivity and 97.7% specificity) to the efficiency reported for otoacoustic emissions and automated auditory brainstem responses. The introduction of bone conduction in the screening reduced the false positive rate from 13.3% to 2.2%. The test duration was 5.3 (± 1.9)min. In 34% of babies only one repetition of the test was needed to raising the result. CONCLUSIONS: The screening test performed quite well in this initial clinical trial, differentiating transient conductive hearing losses from permanent neurosensory impairments and improving the diagnostic efficiency of auditory steady state responses.

New system for neonatal hearing screening based on auditory steady state responses.

NEURONIC-A 6.0 is a system for objective detection of hearing loss by means of the recording and analysis of auditory steady state responses. The system generates digitally Amplitude Modulated tones of different frequencies, allowing the mix of these and the simultaneous presentation through different transducers (earphone and bone vibrator) at different intensities. The system also includes a procedure for artefacts rejection based on the trajectory of variation of the residual noise through time and quantitative indicators or statistics, calculated in the frequency domain, to control the acquisition of the response process and detect automatically the presence or absence of the same. The whole working procedure is automated, which means that once the recording has started, a final result can be obtained in binary form (pass or fail) without the intervention of the examiner.

Cambios con la edad en la respuesta electrofisiológica de seguimiento a la modulación del estímulo acústico / Maturational changes in the human envelope-following responses

Introducción: La capacidad de detectar cambios temporales en la amplitud de modulación de los sonidos del habla es esencial para el adecuado desarrollo y comprensión del lenguaje. El potencial evocado auditivo de seguimiento a la envolvente (PEA-SE) permite estudiar objetivamente la respuesta auditiva a los cambios en la modulación del estímulo acústico en sujetos que no cooperan con exámenes conductuales. Objetivo: Evaluar posibles cambios maduracionales en los parámetros del PEA-SE durante los 2 primeros años de vida. Métodos: se estudiaron 16 bebés normooyentes (12 recién nacidos y 4 bebés de 2 años de edad). Se registró el PEA-SE obtenido con un ruido blanco al que se le realizó un barrido continuo de modulación entre 20-200Hz a 50dB HL. Resultados: Las principales diferencias con respecto al patrón morfológico descrito en los adultos estuvieron a expensas de las frecuencias inferiores a 50Hz, donde el componente P1, a diferencia del P2, no se registró de forma definida y estable en ninguno de los grupos. Con la edad existe, además, un incremento significativo en la amplitud y detectabilidad del potencial en todas las frecuencias de modulación estudiadas. Conclusiones: Se caracterizan por primera vez las modificaciones del PEA-SE con la maduración del sistema auditivo en seres humanos. Los resultados sugieren que el PEA-SE obtenido entre 80-200Hz podría ser útil para estudiar los cambios maduracionales del procesamiento auditivo temporal en la población infantil(AU)

Introduction: The auditory ability to discriminate rapid changes in the envelope of language sounds is essential for speech comprehension. Human envelope-following responses (EFRs) are useful for objective measurement of temporal auditory processing in subjects who are unable to give accurate behavioural responses (e.g., young children). Objective: To evaluate age-dependent changes in EFRs during the first 2 years of life. Methods: The EFRs were recorded in a sample of 16 well babies distributed into 2 age groups (G1: 12 newborns; G2: 4 babies of 2 years). The EFRs were evoked by white noise carrier stimuli with a sweep of modulation frequencies from 20 to 200Hz presented at 50dB HL. Results: The age-related changes affected both morphology and EFR detectability. The main morphological differences were at the expense of frequencies below 50Hz, where the first component P1 was not well defined in either of the 2 age groups. For all modulation frequencies, age significantly affected EFR amplitude and detectability. Conclusions: The present study provides the first evidence on EFR maturation. Some understanding of normal EFR development would facilitate a better use of this technique in clinically-objective measurement of auditory temporal processing in infants who cannot provide reliable behavioural responses(AU)

Maturational changes in the human envelope-following responses.

INTRODUCTION: The auditory ability to discriminate rapid changes in the envelope of language sounds is essential for speech comprehension. Human envelope-following responses (EFRs) are useful for objective measurement of temporal auditory processing in subjects who are unable to give accurate behavioural responses (e.g., young children). OBJECTIVE: To evaluate age-dependent changes in EFRs during the first 2 years of life. METHODS: The EFRs were recorded in a sample of 16 well babies distributed into 2 age groups (G1: 12 newborns; G2: 4 babies of 2 years). The EFRs were evoked by white noise carrier stimuli with a sweep of modulation frequencies from 20 to 200 Hz presented at 50 dB HL. RESULTS: The age-related changes affected both morphology and EFR detectability. The main morphological differences were at the expense of frequencies below 50 Hz, where the first component P1 was not well defined in either of the 2 age groups. For all modulation frequencies, age significantly affected EFR amplitude and detectability. CONCLUSIONS: The present study provides the first evidence on EFR maturation. Some understanding of normal EFR development would facilitate a better use of this technique in clinically-objective measurement of auditory temporal processing in infants who cannot provide reliable behavioural responses.

Caracterización electrofisiológica del potencial evocado auditivo de seguimiento a la modulación del estímulo acústico / Electrophysiological characterisation of envelope-following responses

Introducción: Comprender el lenguaje implica percibir adecuadamente los cambios temporales que se producen en la amplitud de modulación de los sonidos del habla. La detección de estos cambios disminuye en las afecciones neurológicas como la esclerosis múltiple, la neuropatía auditiva, las hipoacusias neurosensoriales, la presbiacusia y el retraso primario del lenguaje. El potencial evocado auditivo de seguimiento a la envolvente (PEA-SE) permite estudiar electrofisiológicamente la respuesta auditiva a los cambios en la modulación de un estímulo acústico. Objetivos: Caracterizar el PEA-SE en adultos sanos y estudiar los efectos del sueño sobre este potencial. Métodos: Se estudiaron 11 sujetos, 6 en condiciones de vigilia y 5 en sueño espontáneo. Se registró el PEA-SE obtenido con un ruido blanco al que se le hizo un barrido de frecuencias de modulación entre 20-200Hz a 50dB HL de intensidad. Resultados: El PEA-SE mostró una morfología similar en todos los sujetos, caracterizándose por presentar dos componentes principales. La amplitud del primer componente (localizado entre 30-50Hz de modulación) fue significativamente mayor que la del segundo componente (entre 80-110Hz) tanto en los sujetos despiertos como en los dormidos. Existió además un efecto significativo del estado de vigilia sobre la amplitud del PEA-SE para las frecuencias entre 88-110Hz, 155-165Hz y 190-200Hz. Sin embargo, no hubo un efecto significativo del sueño sobre los componentes principales del PEA-SE. Conclusiones: En este trabajo se corrobora el patrón morfológico del PEA-SE sustentándose su utilidad para el estudio objetivo del procesamiento temporal del sistema auditivo (AU)

Introduction: The auditory ability to discriminate rapid changes in the envelope of language sounds is essential for speech comprehension. This ability is deteriorated in some neurological diseases such as multiple sclerosis, auditory neuropathy, sensorineural hearing loss, presbycusis, and primary developmental language disorder. Envelope-following responses (EFRs) in humans are useful in objective measurement of temporal processing in the auditory nervous system. Objectives: To evaluate EFRs in healthy younger subjects and to investigate the effects of subject states on the EFRs recorded. Methods: Eleven young subjects were included; 6 of them were awake and 5 were asleep. EFRs were evoked by white noise carrier stimuli with a sweep of modulation frequencies from 20 to 200Hz presented at 50dB HL. Results: The EFRs we recorded were similar in all subjects. There were two principal components. During both subject sleep and wakefulness, the first component (located between 30 and 50Hz) was significantly larger than the second component (located between 80 and 110Hz). There was also a significant effect of sleep on the EFR amplitude for the modulation frequencies between 88 and 110Hz, 155 and 165Hz, and 190 and 200Hz. However, there were no significant effects of sleep on the principal EFR components. Conclusions: These results corroborate the usefulness of the EFR technique for objective measurement of human auditory temporal processing (AU)

[Electrophysiological characterisation of envelope-following responses]. / Caracterización electrofisiológica del potencial evocado auditivo de seguimiento a la modulación del estímulo acústico.

INTRODUCTION: The auditory ability to discriminate rapid changes in the envelope of language sounds is essential for speech comprehension. This ability is deteriorated in some neurological diseases such as multiple sclerosis, auditory neuropathy, sensorineural hearing loss, presbycusis and primary developmental language disorder. Envelope-following responses (EFRs) in humans are useful in objective measurement of temporal processing in the auditory nervous system. OBJECTIVES: To evaluate EFRs in healthy younger subjects and to investigate the effects of subject states on the EFRs recorded. METHODS: Eleven young subjects were included; six of them were awake and five were asleep. EFRs were evoked by white noise carrier stimuli with a sweep of modulation frequencies from 20 to 200Hz presented at 50dB HL. RESULTS: The EFRs we recorded were similar in all subjects. There were two principal components. During both subject sleep and wakefulness, the first component (located between 30-50Hz) was significantly larger than the second component (located between 80-110Hz). There was also a significant effect of sleep on the EFR amplitude for the modulation frequencies between 88-110, 155-165 and 190-200Hz. However, there were no significant effects of sleep on the principal EFR components. CONCLUSIONS: These results corroborate the usefulness of the EFR technique for objective measurement of human auditory temporal processing.

Criterio de parada de la promediación de la respuesta auditiva de estado estable / Stopping criteria for averaging the multiple auditory steady-state response

Introducción y objetivos: El presente estudio pretende examinar la eficiencia de la técnica de promediación para obtener potenciales evocados auditivos de estado estable en sujetos normoyentes y proveer de un criterio de parada cuantitativo a intensidades cercanas al umbral de audibilidad. Métodos: Una mezcla de 4 tonos continuos (500, 1.000, 2.000 y 4.000 Hz) modulados en amplitud entre 89 y 115 Hz, fueron simultáneamente presentados a ambos oídos a una intensidad de 40 dB HL. Fueron promediados un total de 128 segmentos de registro (23,9 min). Resultados: La técnica de promediación aunque resultó eficiente en la mayoría de los casos, no siempre pudo extraer la señal, incluso después de promediarse durante un período prolongado de tiempo. Se propuso además un análisis del ruido de fondo basado en la evaluación de la varianza del ruido en la vecindad de la señal. Conclusiones: Se proponen parámetros cuantificables para ayudar a establecer un criterio deparada de la promediación durante el registro de los potenciales evocados auditivos de estado estable (AU)

Introduction and objectives: The aim of this study was to examine the efficiency of the averaging technique for estimating multiple auditory steady state responses in normal hearing subjects and to provide quantifiable stopping criteria at near-threshold intensities. Methods: Multiple amplitude-modulated (89-115 Hz) tones (500, 1,000, 2,000 and 4,000 Hz) were simultaneously presented to both ears at a fixed intensity of 40 dB HL. A total of 128 data epochs were averaged (23.9 minutes).Results: The results showed that ‘‘classic’’ ensemble averaging, although accurate and time efficient in most cases, could not extract all near-threshold MSSR from noise, even after recording a considerable number of sweeps. The present study also proposed a different approach to evaluate the background noise based on evaluating the mean of the variance close to the signal. Conclusions: The study proposed quantitative parameters to establish stopping criteria during auditory steady-state recordings (AU)

[Stopping criteria for averaging the multiple auditory steady-state response]. / Criterio de parada de la promediación de la respuesta auditiva de estado estable.

INTRODUCTION AND OBJECTIVES: The aim of this study was to examine the efficiency of the averaging technique for estimating multiple auditory steady state responses in normal hearing subjects and to provide quantifiable stopping criteria at near-threshold intensities. METHODS: Multiple amplitude-modulated (89-115 Hz) tones (500, 1,000, 2,000 and 4,000 Hz) were simultaneously presented to both ears at a fixed intensity of 40 dB HL. A total of 128 data epochs were averaged (23.9 minutes). RESULTS: The results showed that "classic" ensemble averaging, although accurate and time-efficient in most cases, could not extract all near-threshold MSSR from noise, even after recording a considerable number of sweeps. The present study also proposed a different approach to evaluate the background noise based on evaluating the mean of the variance close to the signal. CONCLUSIONS: The study proposed quantitative parameters to establish stopping criteria during auditory steady-state recordings.