{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T06:21:54Z","timestamp":1791008514570,"version":"4.1.0"},"reference-count":0,"publisher":"Acoustical Society of America (ASA)","issue":"4","content-domain":{"domain":["pubs.aip.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1995,4,1]]},"abstract":"<jats:p>The 2f1\u2212f2 distortion-product otoacoustic emission (DPOAE) is evoked by two primary tones of frequencies f1&amp;lt;f2, and levels L1 and L2. Previous reports indicate that decreasing L2 below L1=L2 can; (1) increase DPOAE amplitude in normal ears, and (2) increase the degree to which DPOAE amplitudes are reduced by cochlear trauma. Although both of these factors could be advantageous for clinical applications of DPOAEs, neither has been explored in detail. In the present study, 2f1\u2212f2 DPOAE-amplitude frequency functions were collected from normal and impaired ears of rabbits and humans, with L1=L2, and with L2&amp;lt;L1, at each of three values of L1. In rabbits, controlled tonal or noise overexposures were used to produce permanent reductions of DPOAE amplitudes. Comparison of pre- and postexposure DPOAE-amplitude frequency functions demonstrated that the frequency-specific reductions of DPOAEs were enhanced by decreasing L2 below L1. In humans, DPOAE-amplitude frequency functions obtained with the various L1 and L2 combinations were collected from 16 normal ears to provide preliminary normative data for each stimulus-level condition.<\/jats:p>\n               <jats:p>The L1\u2212L2 that produced the maximum DPOAE amplitude in normal ears was systematically dependent on L1. Thus at most frequencies, decreasing L2 below L1=L2 substantially reduced mean DPOAE amplitude when L1\u226575 dB SPL, but increased mean DPOAE amplitudes at L1=65 dB SPL. However, the increase of mean DPOAE amplitude obtained by decreasing L2 below L1=65 dB SPL was small, being less than 3.5 dB at most frequencies. More importantly, at L1=65 dB SPL, L2 could be decreased considerably below L1=L2 without reducing mean DPOAE amplitude relative to that at L1=L2. Inspection of DPOAE-amplitude frequency functions obtained from subjects with mild or moderate sensorineural hearing losses indicated that, in frequency regions of hearing impairment, decreasing L2 below L1 can enhance the degree of reduction of DPOAEs below the corresponding normative amplitudes, without reducing the normative amplitudes. It is concluded that decreasing L2 below L1=L2 has the potential to enhance the performance of DPOAEs in clinical applications.<\/jats:p>","DOI":"10.1121\/1.411959","type":"journal-article","created":{"date-parts":[[2005,10,14]],"date-time":"2005-10-14T19:39:58Z","timestamp":1129318798000},"page":"2346-2358","update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":121,"title":["Dependence of distortion-product otoacoustic emissions on primary levels in normal and impaired ears. I. Effects of decreasing <i>L<\/i>2 below <i>L<\/i>1"],"prefix":"10.1121","volume":"97","author":[{"given":"M. L.","family":"Whitehead","sequence":"first","affiliation":[{"name":"University of Miami Ear Institute, Miami, Florida 33101"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M. J.","family":"McCoy","sequence":"additional","affiliation":[{"name":"University of Miami Ear Institute, Miami, Florida 33101"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B. L.","family":"Lonsbury-Martin","sequence":"additional","affiliation":[{"name":"University of Miami Ear Institute, Miami, Florida 33101"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G. K.","family":"Martin","sequence":"additional","affiliation":[{"name":"University of Miami Ear Institute, Miami, Florida 33101"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"231","container-title":["The Journal of the Acoustical Society of America"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.aip.org\/asa\/jasa\/article-pdf\/97\/4\/2346\/11962417\/2346_1_online.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.aip.org\/asa\/jasa\/article-pdf\/97\/4\/2346\/11962417\/2346_1_online.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,8,4]],"date-time":"2023-08-04T08:35:21Z","timestamp":1691138121000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.aip.org\/jasa\/article\/97\/4\/2346\/971201\/Dependence-of-distortion-product-otoacoustic"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1995,4,1]]},"references-count":0,"journal-issue":{"issue":"4","published-print":{"date-parts":[[1995,4,1]]}},"URL":"https:\/\/doi.org\/10.1121\/1.411959","relation":{},"ISSN":["0001-4966","1520-8524"],"issn-type":[{"value":"0001-4966","type":"print"},{"value":"1520-8524","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[1995,4]]},"published":{"date-parts":[[1995,4,1]]}}}