Effects of Negative Middle Ear Pressure on Distortion Product Otoacoustic Emissions and Application of a Compensation Procedure in Humans

Abstract

Negative MEP substantially decreases DPOAE level for low frequencies and some mid-frequencies but tends to increase DPOAE level for high frequencies. Results suggest that any degree of negative MEP should be corrected to obtain an accurate outcome of DPOAE measurement. The MEP compensation procedure is effective in restoring normal DPOAEs in ears with negative MEPs. Examining changes in DPOAE level under negative MEP allows for further study of the transmission of acoustic signals through an altered middle ear system. A minimal change of DPOAE level at 2000 Hz indicates that the primary resonant frequency of the middle ear is lower than 2000 Hz. The variation in DPOAE change in the middle to high frequency range implies multiple resonances of the middle ear system.

The influence of pressure compensation in the middle ear on the detection of distortion product otoacoustic emissions

“…Široki intervali variranja pritiska u ušnom kanalu od -200 do 200 daPa i nivoa stimulusa od 60 do 90 dB SPL utvrđeni su i u ispitivanju Nevea i saradnika (Naeve, Margolis, Levine & Fournier, 1992), s tim da su intervali variranja u ovom istraživanju veći. San i Šejver u svom istraživanju ukazuju da negativan pritisak u srednjem uvu utiče na emisiju DPOAE na specifičan način, pri čemu su utvrdili povećanje nivoa DPOAE na nekim visokim frekvencijama u prisustvu negativnog pritiska (Sun & Shaver, 2009). …”

“…Uticaj pritiska na parametre OAE u saglasnosti je sa rezultatima istraživanja Sana i Šejvera (Sun & Shaver, 2009) koji ukazuju na veliku varijabilnost uticaja negativnog pritiska u kavumu timpani na DPOAE. Oni su utvrdili smanjenje DPOAE u slučaju rasta negativnog pritiska u srednjem uvu (10 do 12 dB za pritisak od -160 daPa i više).…”

Using a Concha Electrode to Measure Response Patterns Based on the Amplitudes of Cochlear Microphonic Waveforms Across Acoustic Frequencies in Normal-Hearing Subjects

“…Since CM is an electric signal, not an acoustic signal, there will be no issue of acoustic noise, and therefore, measurements at 500 Hz will not require extended averaging time. Another reason for the development of an approach using CM measurements is the fact that both OAEs and CMs are cochlear responses (Dallos 1981;Kusakari et al 1988;Norton et al 1989;Pontonet al 1992;Ferraro & Durrant 2002;Sun & Shaver 2009). As such, interest in the development of an approach using noninvasive narrowband CM measurements is increasing.…”

Response Pattern Based on the Amplitude of Ear Canal Recorded Cochlear Microphonic Waveforms across Acoustic Frequencies in Normal Hearing Subjects

“…One possible alternative is the application of cochlear microphonics (CMs). Both OAEs and CMs are cochlear responses (Dallos, 1981;Ferraro & Durrant, 2002;Kusakari et al, 1988;Norton, Ferguson, & Mascher, 1989;Ponton, Don, & Eggermont, 1992;Sun & Shaver, 2009), and as such, with sufficient research, using CM measurements may become an alternative approach to OAE measurements for assessing cochlear functions (Riazi & Ferraro, 2008;Zhang, 2010;Zhang & Abbas, 1993).…”

“…The OAE has been well studied for clinical applications, and therefore it is commonly used in clinics to assess cochlear functions (Dreisbach & Siegel, 2005;Martin, Stagner, & Lonsbury-Martin, 2011;Sun & Shaver, 2009). For example, distortion product OAEs (DPOAEs) are used in clinics to assess cochlear function with an f 2 frequency at 1000 Hz and above (Gorga et al, 1993;Harrison & Norton, 1999;Suckfull et al, 1996).…”