Variable time-scale modification of speech using transient information

Conventional time-scale modification methods have the problem that as the modification rate gets higher the time-scale modified speech signal becomes less intelligible, because they ignore the effect of articulation rate on speech characteristics. We propose a variable time-scale modification method based on the knowledge that the timing information of transient portions of a speech signal plays an important role in speech perception. After identifying transient and steady portions of a speech signal, the proposed method gets the target rate by modifying steady portions only. The result of subjective preference test indicates that the proposed method produces performance superior to that of the conventional SOLA method.