| 摘要 |
<P>PROBLEM TO BE SOLVED: To automatically adjust a speaker gain in accordance with a noise level by removing voice distortion of a mobile telephone. <P>SOLUTION: When a distortion level of a frequency of a signal exceeds a predetermined value, in a speaker 414 of a mobile telephone, the frequency is filtered by an output filter 402, the signal is further compressed by a compressor 406, and the signal is then supplied via a volume setting logic 410. Furthermore, a gain of the speaker 414 is adjusted to increase the gain in response to increase of a background noise level by a means 408 for setting the background noise level in the environment, in which the mobile telephone is operating, and setting the gain of the speaker based upon the detected background noise level. Thus, voice quality is improved, a volume control button of a telephone is not required, and configuration can be simplified. <P>COPYRIGHT: (C)2010,JPO&INPIT |
