The present invention provides an innovative technique for rapidly and
accurately determining whether two audio samples match, as well as being
immune to various kinds of transformations, such as playback speed
variation. The relationship between the two audio samples is
characterized by first matching certain fingerprint objects derived from
the respective samples. A set (230) of fingerprint objects (231,232),
each occurring at a particular location (242), is generated for each
audio sample (210). Each location (242) is determined in dependence upon
the content of the respective audio sample (210) and each fingerprint
object (232) characterizes one or more local features (222) at or near
the respective particular location (242). A relative value is next
determined for each pair of matched fingerprint objects. A histogram of
the relative values is then generated. If a statistically significant
peak is found, the two audio samples can be characterized as
substantially matching.