本文選題：掃頻刺激聲 + 耳聲發(fā)射�。� 參考：《東北大學(xué)》2014年碩士論文

【摘要】：耳聲發(fā)射現(xiàn)象的發(fā)現(xiàn)是近年來耳科研究的一項(xiàng)重要進(jìn)展,耳聲發(fā)射是耳蝸主動(dòng)產(chǎn)生的一種非常微弱的聲能量,它可以客觀無損地檢測(cè)耳蝸功能狀態(tài),因此在耳科臨床和聽力篩選有著非常廣泛的應(yīng)用。目前,已經(jīng)有很多款耳聲發(fā)射檢測(cè)設(shè)備問世,但都有著檢測(cè)時(shí)間過長,效率不高,且只能檢測(cè)出某些離散頻率點(diǎn)的聽力損失情況的缺點(diǎn)。本文針對(duì)畸變產(chǎn)物耳聲發(fā)射(DPOAE)的提取,設(shè)計(jì)了一套掃頻耳聲發(fā)射檢測(cè)系統(tǒng),能夠很好地解決上述問題。本文首先對(duì)耳聲發(fā)射的概念及其特點(diǎn)進(jìn)行了探討,并引入掃頻刺激聲替換現(xiàn)有的純音刺激聲,使得耳聲發(fā)射檢測(cè)效率大為提升。系統(tǒng)主要分為掃頻刺激聲的產(chǎn)生、DPOAE信號(hào)放大、濾波和采集,USB數(shù)據(jù)傳輸,信號(hào)提取與分析四大模塊,采用TI公司的DSP芯片TMS320VC5509A作為系統(tǒng)中央處理器。其次,介紹了雙通道可控音量刺激聲播放電路的設(shè)計(jì),通過D/A變換和功率放大器將刺激聲數(shù)據(jù)轉(zhuǎn)換刺激聲,為用于誘導(dǎo)人耳產(chǎn)生DPOAE信號(hào),提出“三段式”掃頻刺激聲播放組合,經(jīng)過線性變換,濾除刺激聲。刺激聲誘導(dǎo)產(chǎn)生DPOAE信號(hào)后,通過信號(hào)放大、濾波及其A/D采樣電路,得到24位高精度信號(hào)。隨后,采用USB數(shù)據(jù)接口,完成USB固件和上位機(jī)軟件編程,實(shí)現(xiàn)掃頻刺激聲及其A/D采樣信號(hào)的傳輸,即上位機(jī)將掃頻刺激聲數(shù)據(jù)傳輸?shù)剑篋SP, DSP將A/D采集得到的數(shù)據(jù)傳輸?shù)缴衔粰C(jī),并將數(shù)據(jù)保存。最后介紹了線性變換和閾值截取算法濾除掃頻刺激聲與脈沖噪聲,并通過短時(shí)傅里葉變換得到DPOAE信號(hào)的時(shí)頻曲線,并完成對(duì)系統(tǒng)噪聲優(yōu)越性等性能測(cè)試。
[Abstract]:The discovery of otoacoustic emission is an important development in recent years. Otoacoustic emission is a very weak acoustic energy produced by cochlea initiative, and it can be used to detect the functional state of cochlea objectively. Therefore, it is widely used in ear clinic and hearing screening. At present, there are many otoacoustic emission detection devices, but all have the shortcomings of long detection time, low efficiency, and can only detect the hearing loss of some discrete frequency points. Aiming at the extraction of distortion product otoacoustic emission (DPOAE), a frequency sweep otoacoustic emission detection system is designed in this paper, which can solve the above problems well. In this paper, the concept and characteristics of otoacoustic emission (OAE) are discussed, and the efficiency of otoacoustic emission detection is greatly improved by introducing frequency-sweep stimuli to replace the existing pure acoustic stimuli. The system is mainly divided into four modules: signal amplification, filtering and collecting USB data transmission, signal extraction and analysis. TI's DSP chip TMS320VC5509A is used as the central processor of the system. Secondly, the design of two-channel controllable volume stimulation sound playing circuit is introduced. The stimulatory sound data is converted into stimulatory sound by D- A transform and power amplifier. In order to induce human ear to produce DPOAE signal, a "three-segment" sweep stimulation sound playback combination is proposed. The stimulated sound is filtered by linear transformation. After the DPOAE signal is generated by sound stimulation, the 24 bits high precision signal is obtained by amplifying, filtering and sampling A / D circuits. Then, the USB data interface is used to complete the programming of the USB firmware and the upper computer software, which realizes the transmission of the sweep sound and its A / D sampling signal, that is, the upper computer transmits the scan sound data to the USB, and the DSP transmits the data collected by the A / D to the upper computer. And save the data. Finally, the linear transform and threshold truncation algorithm are introduced to filter the sweep sound and pulse noise. The time-frequency curves of DPOAE signal are obtained by short-time Fourier transform, and the performance of the system noise superiority is tested.
【學(xué)位授予單位】：東北大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TP274;R764
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本文編號(hào)：1795273