利用扫频畸变产物耳声发射实现听力损失的快速检测

Quick Detection of Hearing Loss Using Distortion Product Otoacoustic Emissions Evoked by Swept Tones

畸变产物耳声发射(Distortion Product Otoacoustic Emission,DPOAE)是在两个固定频率的纯音刺激下,由健康人耳主动向外发射的声音能量。DPOAE耳声发射信号的存在与人耳的健康状况密切相关,因而它的检测被广泛用于新生儿听力筛查和成人听力检测。然而,目前的DPOAE检测技术存在操作复杂、分辨率低、测试时间长等不足。本文提出用频率随时间线性增加的扫频信号替代纯音作为刺激声诱发DPOAE耳声发射,以克服当前方法的不足。该扫频方法采用"三段式"播放组合消除刺激声的干扰,并用动态跟踪滤波器从记录到的信号中提取高信噪比的扫频DPOAE信号。实验结果表明,扫频DPOAE检测方法可以大大缩短DPOAE的测量时间,提高检测结果的分辨率,并能灵敏反映受试者听力损失的频率范围。扫频DPOAE检测方法的提出,有利于研制一种快速高效的新型耳声发射检测仪,在临床上协助医生进行准确的听力诊断和治疗。

Distortion product otoacoustic emissions (DPOAEs) are sound energy generated by healthy inner ears when stimulated by two fixed-frequency pure tones. Since DPOAEs are physiologically related with the functional status of the inner ears, DPOAE measurement has been widely used in both hearing screening of newborns and hearing diagnoses of adults. However, there are some limitations in current measurements of DPOAE, such as complex operation, insufficient resolution and low efficiency. In this study, a new method in which frequency-varying swept tones were used to replace pure tones to evoke DPOAEs was proposed to overcome the limitations of current methods. In this method, a three-interval paradigm was employed to eliminate the stimulus artifacts and a dynamic tracking filter was used to extract high-quality swept-tone DPOAEs from the recorded signals. The results show that the swept-tone method can improve both the efficiency and frequency-resolution of current methods. Moreover, the swept-tone DPOAEs within a wide frequency range can help to identify the exact location of the hearing loss. Using swept tones to measure DPOAEs can be beneficial in developing a new type of OAE device with high efficiency to help doctors with accurate diagnoses and appropriate treatments in the clinic.