以消除耳機交互調變失真的方法測量人耳之變頻耳聲傳射

Measuring Distortion Product Otoacoustic Emissions in Human Ears Based on an Earphone Intermodulation Distortion Cancellation Method

陳永慶(Yung-Ching Chen)

指導教授 ： 劉奕汶

國立清華大學/電機資訊學院/電機工程學系所/碩士(2020年)

摘要

變頻耳聲傳射為一種誘發性耳聲傳射，傳統上，變頻耳聲傳射的誘發訊號需要由兩個揚聲器分別發射以避免揚聲器產生失真影響耳聲傳射訊號的正確性。在本篇論文中，首先，我們量測了在不同參數之誘發訊號的揚聲器失真訊號，藉此分析其特性，並且結合文獻中變頻耳聲傳射訊號強度對與誘發訊號的關係，提出了一種新的非線性量測方法，利用揚聲器近似線性的失真成長函數與耳聲傳射的飽和度，使變頻耳聲傳射能夠在僅需一個揚聲器的設備上量測。根據實驗結果，非線性量測方法能克服揚聲器產生的失真，並且得到變頻耳聲傳射訊號; 在空白實驗中，能夠消除大約 25 dB 的揚聲器失真訊號；在耳朵實驗中，非線性量測方式的結果與標準量測方式的結果的相關係數達到 0.61。

關鍵字

耳聲傳射 ； 交互調變失真

並列摘要

The distortion product OAE (DPOAE) is one type of evoked OAEs. Traditionally, DPOAE recording requires two speakers to play the stimulating signals simultaneously to prevent confusion from the distortion generated by the speaker itself. In this research, the relationship between the speaker distortion signals and the stimulation with different parameters was explored. Then combining the property of the DPOAE levels under different situations of the stimulation, we propose a new method, referred to as the nonlinear protocol, to record DPOAEs. The DPOAE signal is obtained with a single speaker by utilizing its saturation property and the approximate linearity of the speaker distortion growth function. Experiment results show that the nonlinear protocol cancels the distortion generated from the speaker and acquires the DPOAEs; in the syringe experiment, the speaker distortion was suppressed about 25 dB; in the ear experiments, the correlation coefficient reaches 0.61 between the result of the nonlinear protocol and the result of the ideal protocol.

並列關鍵字

Otoacoustic emission ； intermodulation distortion

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