TY - JOUR
T1 - Low-frequency and high-frequency distortion product otoacoustic emission suppression in humans
AU - Gorga, Michael P.
AU - Neely, Stephen T.
AU - Dierking, Darcia M.
AU - Kopun, Judy
AU - Jolkowski, Kristin
AU - Groenenboom, Kristin
AU - Tan, Hongyang
AU - Stiegemann, Bettina
N1 - Funding Information:
This work was supported by the NIH (NIDCD R01 DC002251 and P30 DC004662). We thank Sandy Estee for her assistance in subject recruitment, Sarah Michaels for help constructing some of the figures, and the subjects who made the time commitment that was necessary to complete their participation in the study. We also would like to thank Chris Shera and Andy Oxenham for constructive discussions of these data prior to submission, and two anonymous reviewers who provided helpful suggestions on a previous version of the manuscript.
PY - 2008
Y1 - 2008
N2 - Distortion product otoacoustic emission suppression (quantified as decrements) was measured for f2 =500 and 4000 Hz, for a range of primary levels (L2), suppressor frequencies (f3), and suppressor levels (L3) in 19 normal-hearing subjects. Slopes of decrement-versus- L3 functions were similar at both f2 frequencies, and decreased as f3 increased. Suppression tuning curves, constructed from decrement functions, were used to estimate (1) suppression for on- and low-frequency suppressors, (2) tip-to-tail differences, (3) QERB, and (4) best frequency. Compression, estimated from the slope of functions relating suppression "threshold" to L2 for off-frequency suppressors, was similar for 500 and 4000 Hz. Tip-to-tail differences, QERB, and best frequency decreased as L2 increased for both frequencies. However, tip-to-tail difference (an estimate of cochlear-amplifier gain) was 20 dB greater at 4000 Hz, compared to 500 Hz. QERB decreased to a greater extent with L2 when f2 =4000 Hz, but, on an octave scale, best frequency shifted more with level when f2 =500 Hz. These data indicate that, at both frequencies, cochlear processing is nonlinear. Response growth and compression are similar at the two frequencies, but gain is greater at 4000 Hz and spread of excitation is greater at 500 Hz.
AB - Distortion product otoacoustic emission suppression (quantified as decrements) was measured for f2 =500 and 4000 Hz, for a range of primary levels (L2), suppressor frequencies (f3), and suppressor levels (L3) in 19 normal-hearing subjects. Slopes of decrement-versus- L3 functions were similar at both f2 frequencies, and decreased as f3 increased. Suppression tuning curves, constructed from decrement functions, were used to estimate (1) suppression for on- and low-frequency suppressors, (2) tip-to-tail differences, (3) QERB, and (4) best frequency. Compression, estimated from the slope of functions relating suppression "threshold" to L2 for off-frequency suppressors, was similar for 500 and 4000 Hz. Tip-to-tail differences, QERB, and best frequency decreased as L2 increased for both frequencies. However, tip-to-tail difference (an estimate of cochlear-amplifier gain) was 20 dB greater at 4000 Hz, compared to 500 Hz. QERB decreased to a greater extent with L2 when f2 =4000 Hz, but, on an octave scale, best frequency shifted more with level when f2 =500 Hz. These data indicate that, at both frequencies, cochlear processing is nonlinear. Response growth and compression are similar at the two frequencies, but gain is greater at 4000 Hz and spread of excitation is greater at 500 Hz.
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U2 - 10.1121/1.2839138
DO - 10.1121/1.2839138
M3 - Article
C2 - 18397024
AN - SCOPUS:41849108044
SN - 0001-4966
VL - 123
SP - 2172
EP - 2190
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
IS - 4
ER -