| 摘要 |
A personal computer (PC) incorporates a speaker/microphone peripheral, which includes a digital-signal-processor (DSP) based acoustic echo canceler and s upports a plurality of modes of operation. One mode is a video/telecommunications mode . In this mode, the acoustic echo canceler is enabled and the speaker/microphone perip heral provides a monaural dual speaker and microphone for use in video, internet t elephony, etc., communications. Another mode of operation is a multi-media, or wide-ba nd stereo, mode. In this multi-media mode, the acoustic echo canceler is disabled and t he stereo loudspeakers provides high fidelity stereo output signals. In addition, in t his latter arrangement an optional sub-woofer may be additionally coupled to the stereo loudspeakers. The speaker/microphone peripheral switches between the operati ng modes by detecting a predefined sequence of dual-tone-multi-frequency (DTMF) digit s. The DTMF sequences are played from wave-type files stored on the PC.
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