Patent ID: 8326112
Filing Date: 2012-12-04
Classification: G03B,G11B

Abstract:
1. A method for performing a correlation between a test sound signal replayable at variable replay speed and a reference sound signal, which is a digitally stored version of the test sound signal, comprising: determining a measure for the replay speed of a test sound signal; varying a test sampling rate with which the test sound signal is sampled, in order to generate a modified test sound signal depending on the measure for the replay speed, or varying a reference sampling rate of the digitally stored reference sound signal, in order to create a modified reference sound signal depending on the measure for the test replay speed, wherein the test sampling rate or the reference sampling rate are varied so that a deviation between a test replay speed associated with the test sound signal and a reference replay speed associated with the modified reference sound signal is reduced, or that a deviation between a test replay speed associated with the modified test sound signal and a reference replay speed associated with the reference sound signal is reduced, or that a deviation between a test replay speed associated with the modified test sound signal and a reference replay speed associated with a modified reference sound signal is reduced; and comparing the modified test sound signal and the reference sound signal, or the test sound signal and the modified reference sound signal, or the modified test sound signal and the modified reference sound signal, in order to obtain a result of the correlation, wherein the comparing comprises comparing a plurality of reference sound signals each to the same test sound signal, in order to obtain a plurality of comparison results, wherein the plurality of reference sound signals is based on a plurality of mutually different reference sampling rates, and wherein a reference sound signal of the plurality of reference sound signals is the reference sound signal or a modified reference sound signal, wherein the plurality of the comparison results is obtained by correlation, wherein the method further comprises evaluating a quality of the plurality of correlation results, in order to determine a reference sound signal most similar to the test sound signal from the plurality of reference sound signals on the basis of one or a plurality of criteria, wherein the comparing further comprises comparing a first reference sound signal based on a first reference sampling rate to the test sound signal, in order to obtain a first correlation result, comparing a second reference sound signal based on a second reference sampling rate to the test sound signal, in order to obtain a second correlation result, and comparing a third reference sound signal based on a third reference sampling rate to the test sound signal, in order to obtain a third correlation result, wherein the second reference sampling rate is greater than the first reference sampling rate, and the third reference sampling rate is greater than the second reference sampling rate, wherein the evaluating the quality of the plurality of correlation results determines a most similar reference sound signal on the basis of the correlation result, and wherein the varying includes not changing the first, second and third reference sampling rates for a next correlation if the second reference test signal is the most similar reference test signal; increasing the first, second, third sampling rates if the third reference sound signal is the most similar reference sound signal; and reducing the first, second and third reference sampling rates if the first reference sound signal is the most similar reference sound signal.