{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T20:46:26Z","timestamp":1790973986534,"version":"4.1.0"},"reference-count":0,"publisher":"Acoustical Society of America (ASA)","issue":"6","content-domain":{"domain":["pubs.aip.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1996,12,1]]},"abstract":"<jats:p>Distortion product otoacoustic emission (DPOAE) (2\u2009f1\u2212f2) amplitude is dependent upon both the frequency ratio and level separation of the eliciting primary tones. In adults it has been established that, on average, a f2\/f1 ratio of 1.22 is optimal for evoking the most robust DPOAE; DPOAE amplitude is systematically reduced when f2\/f1 ratio is either increased or decreased, thus forming a bandpass function (Harris et\u2008al., 1989). The frequency ratio function (DPOAE amplitude\u00d7f2\/f1 ratio) is thought to reflect the filtering properties of the cochlea (Allen and Fahey, 1993; Brown et\u2008al., 1993). Primary tone level separation also influences DPOAE amplitude, with a 10- to 15-dB level difference between the primary tones (L1&amp;gt;L2) typically generating largest amplitude in adults. Equivalent studies have not been conducted in neonates. The present study evoked the 2\u2009f1\u2212f2 DPOAE in adults, term and premature neonates to define the optimal f2\/f1 ratio and L1\u2212L2 level separation and to investigate the filtering properties of the developing cochlea. Two f2 frequencies were investigated: 1500 and 6000 Hz. F2 was held constant while f1 was varied to produce 13 frequency ratios. Primary tone level separation varied from 15 to 0- in 5-dB intervals. ANOVA were conducted on the resulting f2\/f1 frequency ratio and level separation data. Results showed that the mean optimal frequency ratio for DPOAE generation is comparable in adults and neonates. Also, either a 15- or 10-dB level separation (L1&amp;gt;L2) produced the largest DPOAE amplitude for adults and term neonates whereas DPOAEs from premature neonates appeared to be relatively insensitive to primary tone level separation. The f2\/f1 frequency ratio functions were similar in shape, slope, and bandwidth for adults and neonates, suggesting adult-like cochlear filtering prior to term birth. This finding is in agreement with previous work from our laboratory reporting adult-like DPOAE suppression tuning curves in term-born neonates [Abdala et\u2008al., Hear. Res. (1996)].<\/jats:p>","DOI":"10.1121\/1.417234","type":"journal-article","created":{"date-parts":[[2005,10,17]],"date-time":"2005-10-17T19:55:17Z","timestamp":1129578917000},"page":"3726-3740","update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":83,"title":["Distortion product otoacoustic emission (2\u2009<i>f<\/i>1\u2212<i>f<\/i>2) amplitude as a function of <i>f<\/i>2\/<i>f<\/i>1 frequency ratio and primary tone level separation in human adults and neonates"],"prefix":"10.1121","volume":"100","author":[{"given":"Carolina","family":"Abdala","sequence":"first","affiliation":[{"name":"House Ear Institute, Children's Auditory Research and Evaluation Center, 2100 W 3rd Street, Los Angeles, California 90057"}],"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\/100\/6\/3726\/12162762\/3726_1_online.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.aip.org\/asa\/jasa\/article-pdf\/100\/6\/3726\/12162762\/3726_1_online.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,7,14]],"date-time":"2023-07-14T08:26:05Z","timestamp":1689323165000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.aip.org\/jasa\/article\/100\/6\/3726\/559369\/Distortion-product-otoacoustic-emission-2-f1-f2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1996,12,1]]},"references-count":0,"journal-issue":{"issue":"6","published-print":{"date-parts":[[1996,12,1]]}},"URL":"https:\/\/doi.org\/10.1121\/1.417234","relation":{},"ISSN":["0001-4966","1520-8524"],"issn-type":[{"value":"0001-4966","type":"print"},{"value":"1520-8524","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[1996,12]]},"published":{"date-parts":[[1996,12,1]]}}}