隨著資訊時代的到來，個人通信系統的發展已變得不可或缺，當使用通訊系統時，遠端使用者聽到自己的聲音與近端使用者混在一起，造成通訊品質惡化並使遠端者產生強大的聽覺壓力，此現象稱為聲學迴音。傳統的聲學迴音消除系統是採用指向性麥克風及揚聲器並適當安排其擺放位置，除此之外還使用吸音材料來阻擋因反射造成的迴音，但此裝置的成本過高。本文提出一簡單而有效的聲學迴音消除系統。一個聲學迴音消除系統包含輸入放大器，輸出放大器，低通濾波器，揚聲器室內音場麥克風及以正規化最小均方法的有限脈波響應適應性濾波器之TMDS3260C6701數位信號處理器。模擬及實驗結果顯示在近端沒有音源信號的情形下，無論單頻及隨機信號迴音源皆可在0.16秒內消除，在100Hz至1kHz的頻率範圍之掃頻迴音亦能有效消除。在雙方同時交談的情況下，無論單頻、掃頻及隨機信號迴音源皆可有效消除。因此應用數位信號處理器於聲學迴音消除系統除了能達到即時消除的效果之外，還能達到寬頻的聲學迴音消除。聲學迴音消除系統的發展可有效改善免持聽筒，衛星通訊系統及網路會議系統的品質。

As the advent of the information age, the development of personal communication system has become indispensable. Conventional acoustic echo cancellation employs directional microphone and loudspeaker at proper position and absorbing materials to block the reflected echoes. In this thesis, a simple and effective configuration for acoustic echo cancellation is developed. An acoustic echo cancellation system includes the input amplifier, output amplifier, lowpass filter, loudspeaker enclosure microphone system and the normalized least mean square adaptive control algorithm implemented on TMDS3260C6701 digital signal processor. Simulation and experimental results show that the single tone, swept sine and random echo can be effectively attenuated within 0.16 second by the acoustic echo cancellation system without near end signal. In double talk situation, the acoustic echoes of pure tone, swept sine tone and random signal can also be reduced effectively, and the configuration can achieve broadband acoustic echo cancellation. This development shall significantly improve the quality of hands-free phone, satellite communication system and teleconference system.

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