| 摘要 |
<p>PROBLEM TO BE SOLVED: To allow a portable telephone set to make a speech in a public place without giving nuisance to surrounding persons. SOLUTION: A telephone set is provided with a digital signal processing circuit 5 that applies amplification processing to a transmission voice signal, and when an automatic sound volume adjustment key 22A is operated at a speech start or during a speech, a control section 20 detects it to provide an output of an amplification instruction signal of the transmission voice to the digital signal processing circuit 15. Then the digital signal processing circuit 15 increases the range of voice data picked up by a microphone 19 and outputted from a voice CODEC 14 up to a prescribed voice range and amplifies the data so that the level of the voice signal increased up to a prescribed sound frequency band reaches a prescribed level, and the result is outputted to a channel CODEC 16. As a result, even when a talker speaks in a low voice during the speech, the voice signal is increased up to a prescribed voice range and amplified, and the amplified signal is sent to a base station via the channel CODEC 16, a MODEM modulator 17, a ratio transmission reception section 11 and an antenna AT, thus the signal is sent to a speech opposite party as a proper voice.</p> |
