Relationship Between Distortion Product - Otoacoustic Emissions (DPOAEs) and High-Frequency Acoustic Immittance Measures.

BACKGROUND Pathologies that alter the impedance of the middle ear may consequently modify the DPOAE amplitude. The aim of this study was to correlate information from 2 different clinical procedures assessing middle ear status. Data from DPOAE responses (both DP-Gram and DP I/O functions) were correlated with data from multi-component tympanometry at 1000 Hz.

Correlation between DPOAE I/O functions and pure-tone thresholds.

Unlabelled: Different studies have been carried out in order to correlate audiometric thresholds and distortion product otoacoustic emissions measurements (DPOAE). However, high variability and external interferences make hearing thresholds estimates by means of the DPOAE very little sensitive. The aim of this study was to check the correspondence between the pure tone thresholds and the cochlear response thresholds by DPOAE Input/output functions, considering the influence of the following variables: gender, past of acute otitis media, and ear side.

Contralateral suppression of otoacoustic emissions: input-output functions in neonates.

Background: The literature suggests that contralateral acoustic stimulation (CAS) alters the amplitude of the distortion product otoacoustic emissions (DPOAEs), but it is still unknown whether the DPOAE Input/Output (I/O) functions are also affected. To elucidate this aspect of the DPOAEs, the present study assessed the effects of CAS on DPOAE I/O functions at the frequencies of 2 kHz and 4 kHz, in a sample of term neonatal subjects.

Material/methods: Sixty randomly selected neonates were included in the study.

Latency of DPOAE in milliseconds and waves.

Unlabelled: The latency of Distortion Product Otoacoustic Emissions is defined as the time interval between the wave onset from initial stimulation and the return to the ear canal.

Aim: The aim of this research was to verify the latency of the distortion product otoacoustic emissions in normal hearing adults, analyzing the influence of the gender, ear, frequencies and measurements.

Study Design: clinical prospective.