Wow Detection and Compensation Employing Spectral Processing of Audio
Andrzej Czyżewski, M. Dziubiński, Andrzej Kaczmarek, Bożena Kostek, Przemysław Maziewski · Journal of the Audio Engineering Society · 2004
The engineered algorithms are presented for the detection of parasitic frequency modulation in audio originating from irregularities of sound carrier velocity. The algorithms were developed with special regard to non-periodic frequency modulation effects found in old movie sound tracks. The proposed algorithms consider the influence of the wow disturbance on the location of formants in time-frequency representation. The dynamic analysis of formant structures behavior underlies discriminating between parasitic frequency changes and natural frequency fluctuations. The compensation of the detected wow-related frequency modulation is accomplished basing on the non-uniform resampling algorithm, driven by the discerned parasite modulation patterns. The details of the proposed wow detection and compensation techniques are presented and achieved results are discussed.