Reducing reflected contributions to ear-canal distortion product otoacoustic emissions in humans

Tiffany A. Johnson, Stephen T. Neely, Judy G. Kopun, Michael P. Gorga

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


Distortion product otoacoustic emission (DPOAE) fine structure has been attributed to the interaction of two cochlear-source mechanisms (distortion and reflection sources). A suppressor presented near the 2 f1 - f2 frequency reduces the reflection-source contribution and, therefore, DPOAE fine structure. Optimal relationships between stimulus and suppressor conditions, however, have not been described. In this study, the relationship between suppressor level (L3) and stimulus level (L2) was evaluated to determine the L3 that was most effective at reducing fine structure. Subjects were initially screened to find individuals who produced DPOAE fine structure. A difference in the prevalence of fine structure in two frequency intervals was observed. At 2 kHz, 11 of 12 subjects exhibited fine structure, as compared to 5 of 22 subjects at 4 kHz. Only subjects demonstrating fine structure participated in subsequent measurements. DPOAE responses were evaluated in 13 -octave intervals centered at 2 or 4 kHz, with 4 subjects contributing data at each interval. Multiple L3 's were evaluated for each L2, which ranged from 20 to 80 dB SPL. The results indicated that one or more L3 's at each L2 were roughly equally effective at reducing DPOAE fine structure. However, no single L3 was effective at all L2 's in every subject.

Original languageEnglish (US)
Pages (from-to)3896-3907
Number of pages12
JournalJournal of the Acoustical Society of America
Issue number6
StatePublished - Jun 2006

ASJC Scopus subject areas

  • Arts and Humanities (miscellaneous)
  • Acoustics and Ultrasonics

Fingerprint Dive into the research topics of 'Reducing reflected contributions to ear-canal distortion product otoacoustic emissions in humans'. Together they form a unique fingerprint.

Cite this