[Evoked otoacoustic emissions in school children]. / Otoemisiones acústicas evocadas en escolares.

OBJECTIVE: The aim of this work was to determine the usefulness of evoked otoacoustic emissions (OEAE) as a screening method for the diagnosis of hearing loss in schoolchildren. PATIENTS AND METHODS: To this end and by using this method, we have studied 1,202 ears of 616 children in the 1st and 2nd grades of elementary school with a mean age of 6.2 years. The equipment employed was an Otodynamic Analyzer (ILO 88) by Otodynamics, Ltd and the program ILO 88, version 3.94. RESULTS: The results were OEAE positive in 1,041 ears (86.6% passed the test) and OEAE negative in 161 ears (13.4% failed the test). We have determined the percentiles of all the parameters of the test and of the responses in order to establish the normal values in this age group. CONCLUSIONS: The use of the OEAE for the detection of hearing loss should not be restricted to newborns. The OEAE can also be used as an auditive screening test in schoolchildren.

[Recording of evoked otoacoustic emissions in adult normal hearing population. Percentile of normalcy]. / Registro de otoemisiones provocadas en población adulta normoyente: percentiles de normalidad.

Evoked otoacustic emissions recording hold some promise as a fast objective and non-invasive audiological procedure to study the cochlea at the outer hair cell level. This study has been made in 100 voluntary normal hearing adults. We evaluate the auditory system by means of evoked otoacustic emissions with a non-linear click. This report resumes methods and results in these normal grown-up ears.

[The study of evoked otoacoustic emissions in children]. / Estudio de otoemisiones acústicas provocadas en niños.

We evaluated the auditory system of 41 children by means of evoked otoacoustic emission. The children were selected from a school population and range in age from 3 to 16 years. No hearing problems were detected prior to this study. The stimulus was a nonlinear click with a frequency of 21/s. All the children but one had echo sizes over 9.72 dB SPL. The mean echo size was 13.23 dB SPL with a reproducibility of 74.81%. Average echo sizes for each frequency are presented. There were no significant differences in the series with respect to the adult comparative pattern used except for the child with an unknown perceptive disorder. We conclude that the test is reliable and highly sensitive, and that it detects small conductive and sensory hearing losses. It is fast, easy, painless and does not require sedation, making it particularly interesting for hearing assessments in childhood.

[Comparative study of tonal liminal audiometry and evoked otoacoustic emissions in school screening programs]. / Estudio comparativo entre audiometría tonal liminar y otoemisiones evocadas en las revisiones escolares.

Early diagnosis of deafness is an important objective during the pediatric age. This study compares two different audiological techniques, otoacoustic emissions (OEA) and tonal audiometry (AUD), to be used as screening methods in school revisions programmed for 6 years olds. The correlation between techniques is very good (97% of the positives and 92% of the negatives). The OEA method is objective and faster if the environmental noise is low; if not, AUD seems to be more reliable. At this age (6 years), the otoacoustic emissions have characteristics of the adult age.

[The usefulness of provoked acoustic otoemissions in the study of olivo-cochlear reflex]. / Utilidad de las otoemisiones acústicas provocadas en el estudio del reflejo olivo-coclear.

The paper reports the experimental task done by the AA, in order to probe objectively the being of a feed-back circuit of cochlear interconnexion. This loop is basically represented by the medial efferent olivo-cochlear system. With that purpose they have analyzed the variations produced in the provoked acoustic otoemissions by clicks registered in one ear when the contralateral ear is stimulated with a white noise of 80 dB HL. The results shows that after stimulation of the contralateral cochlea with a white noise a decrease of the global amplitude of the PAOE is observed and also a decrease of the several amplitudes composing the frequency spectrum, but retaining the same morphological pattern.

[Influence of the contralateral acoustic stimulation on the acoustic otoemissions: response modulation by the efferent olivocochlear system]. / Influencia de la estimulación acústica contralateral sobre las otoemisiones acústicas: modulación de la respuesta por el sistema eferente olivococlear.

We have correlated in 16 patients (32 ears), the modifications de EOEs before and after sound stimulation of the contralateral ear. The recording of the EOEs has been performed in a sound proof room with ILO 88 from Otodynamics Ltd., the analysis has been made with the ILO 88 V.3.5 software. We have tried to study the modulator rol of the medial efferent coclear system on the external ciliated cells. In the results we observe a decrease of the amplitude in the EOEs when the contralateralmears is stimulated a white noise, in relation with the nonstimulation situation. When pures tones are used contralateral stimulation the decrease in the EOEs amplitude takes place in the same frequency spectrum as the pure tone used.