| 摘要 |
A telecommunications testing apparatus comprising a signal generator (7) which generates a speech-like synthetic signal, which is supplied to the input of a telecommunication apparatus (1) to be tested. The distorted oupput of the telecommunications apparatus (1) is supplied to an analysis means (8), which derives, for both the undistorted test signal and the distorted signal from the telecommunications apparatus (1), a measure of the excitation of the human auditory system generated by both signals, taking into account both spectral masking and temporal masking phenomena. The difference between the two excitations is then calculated, and a measure of the loudness of the difference is derived which is found to indicate to a high degree of accuracy the human subjective response to the distortion introduced by the telecommunications system. |
