Time-scale modification of music using a synchronized subband/time-domain approach

Time-domain audio time-scaling algorithms are efficient in comparison to their frequency-domain counterparts, but they rely upon the existence of a quasi-periodic signal to produce a high quality output. This requirement makes them unsuitable for direct application to complex multi-pitched signals such as polyphonic music. However, it has been shown that applying time-domain algorithms on a subband basis can resolve this issue. Existing subband/time-domain approaches result in a reverberant/phasy artifact being introduced into the output due to poor synchronization between time-scaled subbands. This paper presents a number of synchronization schemes that greatly reduce the amount of reverberation/phasiness introduced into the time-scaled output by existing subband/time-domain approaches.