| 摘要 |
PURPOSE:To reproduce pseudo sounds with a high sound quality without using any parts to be used exclusively for pseudo sounds only by preparing two kinds of systems of a adaptive differential system and logarithmic compressing system to a coding/decoding device for sounds and pseudo sounds. CONSTITUTION:Analog sounds inputted from a microphone 1 are amplified by means of an amplifier 2 and digitized at an A/D converter 3. Then the digitized sound data are simultaneously inputted to a switch 9 and frequency measuring instrument 4 and the instrument 4 measures the frequency of the inputted sounds and outputs the measured frequency to a coding system selector 5. The selector 5 selects an adaptive differential system 6 when the frequency is in a sound band or a logarithmic compressing system 7 when the frequency is in a pseudo sound band and sends a selected result to switches 9 and 10. The switches 9 and 10, on the other hand, are actuated upon receiving the selected result so that the data can flow to the encoder of the selected system. Therefore, parts which are exclusive used for pseudo sounds only are not required and the pseudo sounds can also be reproduced with a high sound quality. |
