MEASURING DEVICE FOR DIGITAL TELEPHONE SET

摘要

PURPOSE:To measure the calling performance of a digital telephone set with high accuracy by converting a digital signal outputted from the telephone set into the linear PCM signal with addition of a reference pseudo sound signal and measuring the calling performance of the telephone based on the linear PCM signal. CONSTITUTION:The reference pseudo sound digital signal stored in the 1st memory 29 is outputted through an artificial mouth 11 and received by a microphone with no intervention of a digital telephone set 1. A digital frequency analyzer 49 of a measurement circuit 13 performs a spectrum analysis and the spectrum analysis result of the reference pseudo sound digital signal is stored in a floppy disk 19 with no intervention of the telephone set 1. The pseudo sound signal outputted through the mouth 11 is received by a transmitter microphone 5b of the telephone set 1 and supplied to a circuit 41. Then the logarithmic PCM signal is converted into the linear PCM signal and undergoes spectrum analysis through the analyzer 49. The result of this analysis is stored in the disk 19 and undergoes comparison through a microcomputer 15. Thus the sending speech sensitivity is secured.