The objective of the study was to assess the safety of the HyperSound® Audio System (HSS), a novel audio system using ultrasound technology, in normal hearing subjects under normal use conditions; we considered pre-exposure and post-exposure test design. We investigated primary and secondary outcome measures: i) temporary threshold shift (TTS), defined as >10 dB shift in pure tone air conductio...

Low-frequency otoacoustic emissions (OAEs) are often concealed by acoustic background noise such as those from a patient's breathing and from the environment during recording in clinics. When using electrocochleaography (ECochG or ECoG), such as cochlear microphonics (CMs), acoustic background noise do not contaminate the recordings. Our objective is to study the response pattern of CM waveform...

BACKGROUND Due to high sound pressure levels (SPLs), noise produced by jet planes may be harmful to hearing of people working in their proximity. The aim of this study was to assess the effects of exposure to jet engine noise on technical staff hearing. MATERIAL AND METHODS The study comprised 60 men, aged 24-50 years, employed in army as technical staff and exposed to jet engine noise for 6-...

The behavioral evaluation of hearing in very young infants has been fraught with procedural and interpretive problems. Despite the introduction of current physiological techniques of estimating hearing sensitivity, such as otoacoustic emissions and auditory brainstem-evoked responses, behavioral hearing assessment of young infants remains of interest to researchers of infant behavior and to cli...

High-resolution measurements of distortion product otoacoustic emissions (DPOAEs) from three different experimental paradigms are shown to be in agreement with the implications of a realistic "two-source" cochlear model of DPOAE fine structure. The measurements of DPOAE amplitude and phase imply an interference phenomenon involving one source in the region of strong nonlinear interaction of the...

BACKGROUND The aim of this study was to evaluate the repeatability and variability of TEOAE characteristics in hearing screening tests performed under practical conditions on normal subjects. MATERIAL/METHODS A group of 11 young, normal-hearing subjects aged 19-24 years was tested. They were examined otologically and audiologically prior to the tests and no ear pathologies were found. Respons...

The compound action potential (CAP) that can be recorded from the exposed intracranial portion of the eighth nerve in man to stimulation with broadband clicks of about 100 dB Pe SPL normally has an initial (small) positivity followed by a sharp negative peak with a latency of about 3 to 3.5 ms. The negative peak is usually followed by another positive-negative deflection with a latency of about...

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 cochlea...

Health technology Two universal newborn hearing screening programmes, one using automated auditory brainstem response (AABR) and the other transient evoked otoacoustic emissions (TEOAE), were examined. Detailed pass criteria were reported for both programmes. The main difference between the two screening approaches was that AABR was performed by neonatal nurses, while TEOAE was conducted by mas...

UNLABELLED The hormonal changes that occur in a short time span promote modifications all over the woman's body, with physical and emotional manifestations which are frequently observed. AIM to evaluate the activity of the external ciliated cells in women during their menstrual cycle, observing the effect of hormonal changes caused by the cycle in their 3 phases. METHODS this is a longitudi...