The feature of ISD (Individual Speech Devices)is that it adopts direct analogue record and access technique,and that the speech signals,in its original form recorded into the analogue memory devices directly and saved for long.

• ISD单片语音器件的独特之处，是采用直接模拟存储技术，语音信号以其原本的模拟形式直接存入模拟量存储器中并长远保存。