Details

Autor(en) / Beteiligte

• Purcell, David W.
• Van Roon, Patricia
• Sasha John, M.
• Picton, Terence W.

Titel

Simultaneous latency estimations for distortion product otoacoustic emissions and envelope following responses

Ist Teil von

• The Journal of the Acoustical Society of America, 2006-05, Vol.119 (5), p.2869-2880

Ort / Verlag

Woodbury, NY: Acoustical Society of America

Erscheinungsjahr

2006

Quelle

AIP Journals Complete

Beschreibungen/Notizen

• The purpose of this research was to simultaneously estimate processing delays in the cochlea and brainstem using the same acoustic stimuli. Apparent latencies were estimated from ear canal measurements of 2 f 1 - f 2 distortion product otoacoustic emissions (DPOAEs), and scalp recordings of the f 2 - f 1 envelope following response (EFR). The stimuli were equal level tone pairs ( 65 dB SPL) with the upper tone f 2 set at either 900 or 1800 Hz to fix the initiation site of the DPOAE and EFR. The frequency of f 1 was swept continuously between frequency limits chosen to keep the EFR response between 150 and 170 Hz . The average DPOAE latencies were 9.6 and 6.2 ms for f 2 = 900 and 1800 Hz , and the corresponding EFR latencies were 12.4 and 8.8 ms . In a control condition, a third (suppressor) tone was added near the DPOAE response frequency to evaluate whether the potential source at f dp was contributing significantly to the measured emission. DPOAE latency is the sum of both inward and outward cochlear delays. The EFR apparent latency is the sum of inward cochlear delay and neural processing delay. Neural delay was estimated as approximately 5.3 ms for both frequencies of stimulation.