1. A method for extracting acoustic fingerprints for common recordings comprising the steps of: a. identifying segments of interest from a dataset of recordings by a means of classification using a Call Progress Analysis system; b. generating acoustic fingerprint candidates for said identified segments, each of the acoustic fingerprint candidates being computed from a plurality of power spectrums of the corresponding one of the identified segments, each of the power spectrums comprising a plurality of frequency bands; c. adding said acoustic fingerprint candidates to an acoustic fingerprint database; d. repeating steps (a) and (b) to process the recordings in the dataset using the acoustic fingerprint database containing said acoustic fingerprint candidates added in step (c); and e. removing said acoustic fingerprint candidates from the acoustic fingerprint database that were not detected a specified number of times.