| 摘要 |
<p>An audibly distinctive test signal provided by a generator (6) is a pink noise signal at a standard level with periodic but brief interruptions (optimized for the ear's memory for level and spectral differences) acting as an identifier. The test signal is applied to a recording medium or transmission channel (14), preferably via an equalizer (16) and gain setting means (181. The test signal recovered from the recording medium or transmission channel by playback or receiving means (22) is compared and matched to a reference uninterrupted pink noise signal provided at a standard level by a generator (24). The interruptions are used to switch between the test and reference signals and to provide via equalizer (34) and speaker (28) an audible cue as to the identity of the signal heard at any moment so that a rapid confirmation and adjustment, if necessary, of recording/reproduction or transmis- sion/reception calibration can be achieved primarily by ear and, if desired, also by applying the signals to measuring instruments, such as a meter (30) and spectrum analyser (32).</p> |
