Patent ID: 6097819
Filing Date: 2000-08-01
Classification: H04R

Abstract:
A method for testing noise of a record/play-back loop in an audio system of a personal computer (PC) system, the audio system comprises an analog-to-digital (A/D) converter, an FM synthesizer, an FM register, a mixer, an output device, an input device, and a connection element connected between the output device and the input device, the PC system has a system bus for communicating with the A/D converter and the FM synthesizer, comprising the steps of:(a) the PC system is started to perform an imbedded test software, and then the PC system issues a command to the FM synthesizer to output a sinusoidal analog signal to the output device via the mixer;(b) the analog signal is outputted to the input device via the connection element and then is outputted to the A/D converter;(c) the analog signal is converted to a digital signal by the A/D converter;(d) the digital signal is stored as an digitized audio document in the A/D converter;(e) the PC system performs a mathematical analysis on the digitized audio document in order to calculate a signal-to-noise (S/N) ratio and a signal distortion of the record/play-back loop of the audio system; and(f) the S/N ratio and the signal distortion described in step (e) are compared with a pair of predetermined standards respectively in order to determine that whether the S/N ratio and the signal distortion meet the predetermined standards.