We characterized the 2F1-F2 distortion product reflected in the human frequency-following response (FFR). In the first experiment, we evaluated the input-output growth functions of the distortion product at 2F1-F2 (FFR-DP) for three primary pairs. In the second experiment, we tested the effect of primary tone level variation on the FFR-DP. The results for all three stimulus pairs showed that wh...

Similarities and differences in distortion-product otoacoustic emissions (DPOAEs) among four Food and Drug Administration (FDA) approved devices were assessed quantitatively. DPOAEs were recorded from 42 adult subjects (84 ears) ranging in age from 19 to 40 years. All subjects had hearing thresholds of 20 dB HL or better for the test frequencies from 0.25 to 8.0 kHz and normal acoustic immittan...

The present study investigates the effect of small amounts of outer hair cell (OHC) loss on distortion product otoacoustic emission (DPOAE) levels and evoked potential permanent threshold shifts (PTS) in a population of 12 noise-exposed chinchillas. The group mean DPOAE level, which decreased by up to approximately 15 dB in the presence of less than 8 dB PTS and 15% OHC loss, indicates that DPO...

Distortion product otoacoustic emissions (DPOAEs) recorded in the ear canal are a composite or vector sum of two underlying components. The relationship between hearing thresholds and DPOAE-component level, rather than composite level, has been of recent interest. Two different signal-processing methods, inverse fast Fourier transform (IFFT) with time-windowing and low-pass filtering, were used...

Otoacoustic emissions are low-intensity sounds that are produced by cochlea. The aim was to evaluate of the click evoked otoacoustic emission /TEOAE/ and distortion-product otoacoustic emission /DPOAE/ before and after shooting and compare it with conventional pure tone audiometry. Ten male soldiers /20 ears/ were exposed to impulse noise /15 single rounds of live ammunition at the maximum C-we...