Plinkert P K, Bootz F, Vossieck T
Department of Otolaryngology, University of Tübingen, Germany.
Eur Arch Otorhinolaryngol. 1994;251(2):95-9. doi: 10.1007/BF00179900.
Otoacoustic emissions (OAE) are influenced in their amplitude and frequency spectra by the middle ear. The effects of changes in the middle ear transmission mechanisms on transiently evoked OAE (TEOAE) and distortion product emissions (DPOAE) were investigated as a function of static ear canal pressure in 25 normal-hearing test persons aged 18-35 years. The ear canal pressure was varied stepwise between positive and negative values of 200 daPa. TEOAE and DPOAE amplitudes were attenuated significantly with changes of the static ear canal pressure, with greatest changes at low frequencies (< 2 kHz). The alterations of OAE amplitude were slightly dependent on the polarity of the pressure, with positive pressure producing a greater attenuation (0.6 dB). The results demonstrate that changes in middle ear impedance can cause a misinterpretation of OAE. To avoid this problem, tympanometry should always precede OAE measurements. Alternatively, both methods can be combined using one acoustic probe, so that the emissions can be evoked at the peak of middle ear compliance.
耳声发射（OAE）的幅度和频谱受中耳影响。在25名年龄在18 - 35岁的听力正常的测试者中，研究了中耳传导机制变化对瞬态诱发耳声发射（TEOAE）和畸变产物耳声发射（DPOAE）的影响，并将其作为外耳道静态压力的函数。外耳道压力在200 daPa的正负值之间逐步变化。随着外耳道静态压力的变化，TEOAE和DPOAE的幅度显著衰减，在低频（<2 kHz）时变化最大。耳声发射幅度的改变略微依赖于压力的极性，正压产生更大的衰减（0.6 dB）。结果表明，中耳阻抗的变化会导致对耳声发射的错误解读。为避免此问题，在进行耳声发射测量之前应始终先进行鼓室导抗测量。或者，两种方法可以使用一个声学探头进行组合，以便在中耳顺应性峰值处诱发耳声发射。
