The phase versus frequency function of the distortion product otoacoustic emission (DPOAE) at 2f(1) - f(2) is approximately invariant at frequencies above 1.5 kHz in human subjects when recorded with a constant f(2)/f(1). However, a secular break from this invariance has been observed at lower frequencies where the phase-gradient becomes markedly steeper. Apical DPOAEs, such as 2f(1) - f(2), ar...

BACKGROUND A noninvasive method to monitor changes in intracranial pressure (ICP) is required for astronauts on long-duration spaceflight who are at risk of developing the Visual Impairment/Intracranial Pressure syndrome that has some, but not all of the features of idiopathic intracranial hypertension. We assessed the validity of distortion product otoacoustic emissions (DPOAEs) to detect chan...

This study examined the association between ultrahigh-frequency (UHF) hearing sensitivity and distortion-product otoacoustic emission (DPOAE) levels at conventional frequencies. Behavioral thresholds were measured from 2 through 16 kHz, and DPOAE levels were measured at discrete f2 frequencies between 2 through 8 kHz in 553 young normal-hearing adult male participants. A DPOAE frequency sweep w...

PURPOSE To verify the association between the amplitude of distortion-product otoacoustic emissions (DPOAE) and biomarkers of oxidative stress (OS) in resident students of the tobacco-producing region. METHODS Participated in the study group (SG) 21 normal-hearing students from the tobacco-producing region, and in the control group (CG) 25 normal-hearing students who did not live in the count...

Differences in auditory thresholds and distortion-product otoacoustic emission (DPOAE) levels were investigated as a function of gender, ear, frequency, and experimental condition: quiet sedentary activity, exercise, noise, and exercise and noise combined. In general, participants displayed significant elevations in auditory thresholds of approximately 6 to 13 dB following the two conditions em...

Contralateral acoustic stimulation (CAS) with white noise and pure tone stimuli was used to assess frequency specificity of efferent olivocochlear control of cochlear mechanics in the gerbil. Changes of the cochlear amplifier can be monitored by distortion product otoacoustic emissions (DPOAEs), which are a byproduct of the nonlinear amplification by the outer hair cells. We used the quadratic ...

OBJECTIVES The primary goal of this study was to test the ability of 2f1-f2 distortion-product otoacoustic emissions (DPOAEs) to detect reduced cochlear function in the presence of normal behavioral sensitivity. DESIGN A prospective study was performed in normal-hearing young adults using simple and complex regression analyses to clarify the relationship between ultra-high frequency (UHF) hea...

UNLABELLED Exposure to occupational noise may cause injuries to the inner ear, and the distortion product otoacoustic emissions (DPOAE) may identify initial auditory alterations, thus assisting NIHL early diagnosis. AIM The goal of this study was to evaluate DPOAE as a method to diagnose early physiopathological alterations caused by occupational noise exposure. STUDY DESIGN Transversal. ...

OBJECTIVES Distortion-product otoacoustic emission (DPOAE) stimulus calibrations are typically performed in sound pressure level (SPL) before DPOAE measurements. These calibrations may yield unpredictable DPOAE response levels, presumably because of the presence of standing waves in the ear canal. Forward pressure level (FPL) has been proposed as an alternative method for stimulus calibration b...

stapedotomy. Materials and Methods: The diameters of prostheses used were 0.3 mm and 0.6 mm in two groups of ten patients. and 10 healthy patients as control group were included. Transient evoked otoacoustic emissions (TEOAE), Distortion product otoacoustic emissions (DPOAE) and DPOAE I/O functions were recorded. Results: Significant changes were detected at 2000-3000 Hz (p<0.001) and 4000-6000...