Loudness growth prediction using normal templates of loudness derived with ABR and DPOAE measures was investigated in 20 children 4 to 12 years and 20 adults with normal hearing. An ABR click latency-intensity function (LIF), ABR 2 kHz tone LIF, and DPOAE 2 kHz amplitude-intensity function (AIF) were recorded from each listener. A loudness-intensity function was also measured for each electroph...

OBJECTIVES Mediated by the medial olivocochlear system (MOCS), distortion product otoacoustic emission (DPOAE) levels are reduced by presentation of contralateral acoustic stimuli. Such acoustic signals can also evoke a middle ear muscle reflex (MEMR) that also attenuates recorded DPOAE levels. Our aim is to clearly differentiate these two inhibitory mechanisms and to analyze each separately, p...

OBJECTIVES The use of a suppressor tone has been proposed as the method of choice in obtaining single-generator distortion product (DP) grams, the speculation being that such DP grams will be more predictive of hearing thresholds. Current distortion product otoacoustic emissions (DPOAE) theory points to the ear canal DPOAE signal being a complex interaction between multiple components. The effe...

OBJECTIVES To investigate the effects of isoflurane and propofol on mean arterial pressure (MAP), cochlear blood flow (CoBF), distortion-product otoacoustic emission (DPOAE), and the ultrastructure of outer hair cells (OHCs) in guinea pig cochleae. METHODS Forty-eight male guinea pigs were randomly assigned to one of six treatment groups. Groups 1 to 3 were infused (i.v.) with a loading dose ...

Distortion product otoacoustic emissions (DPOAEs) measured in the ear canal represent the vector sum of components produced at two regions of the basilar membrane by distinct cochlear mechanisms. In this study, the effect of stimulus level on the 2f(1) - f(2) DPOAE phase was evaluated in 22 adult subjects across a three-octave range. Level effects were examined for the mixed DPOAE signal measur...

A number of commercial distortion product otoacoustic emission (DPOAE) systems are available. Each system uses a slightly different signal processing approach . As a result, calculations commonly used to quantify the quality of collected DPOAE data (such as noise level and signal to noise ratio) differ across systems. In this report, the theory underlying DPOAE noise estimation is reviewed and ...

Distortion product otoacoustic emission (DPOAE) iso-suppression tuning curves (STC) were generated in 15 normal-hearing adults and 16 healthy term-born neonates for three f2 frequencies. The 2f1-f2 DPOAE was elicited using f2/f1 = 1.2, LI = 1.2, LI = 65 and L2 = 50 dB SPL. A suppressor tone was presented at frequencies ranging from 1 octave below to 1/4 octave above f2 and varied in level until...

OBJECTIVES (1) To determine the ototoxicity detection rate (sensitivity) for distortion-product otoacoustic emissions (DPOAEs) testing in adults who received ototoxic medications and experienced pure-tone threshold changes during the course of treatment; (2) to determine the extent to which DPOAE sensitivity to ototoxicity depends on the type of drug administered (platinum or antibiotic), magni...