APPARATUS AND METHOD FOR PERFORMING A CORRELATION BETWEEN A TEST SOUND SIGNAL REPLAYABLE AT VARIABLE SPEED AND A REFERENCE SOUND SIGNAL

摘要

Disclosed is an apparatus for establishing a correlation between a test audio signal (270) playable at a variable speed and a reference audio signal (274) representing a digitally stored version of the test audio signal (270). Said comprises means (210) for determining a measure of a playing speed of the test audio signal (270), means (230) for varying a test sampling rate at which the test audio signal (270) is sampled so as to generate a modified test audio signal (272) in accordance with the measure of the test playing speed or for varying a reference sampling rate of the digitally stored reference audio signal (274) so as to create a modified reference audio signal (276) in accordance with the measure of the test playing rate. The varying means (230) is configured for varying the test sampling rate or the reference sampling rate such that a deviation between a test playing rate assigned to the test audio signal (270) or a reference playing speed allocated to the modified reference audio signal (276) is reduced or a deviation between a test playing speed assigned to the modified test audio signal (272) and a reference playing speed allocated to the reference audio signal (274), or a deviation between a test playing speed assigned to the modified test audio signal (274) and a reference playing speed allocated to a modified reference audio signal (276), is reduced. The inventive apparatus further comprises means (250) for comparing the modified test audio signal (272) and the reference audio signal (274), or the test audio signal (270) and the modified reference audio signal (276), or the modified test audio signal (272) and the modified reference audio signal (276), in order to obtain a result of the correlation.