On bedrosian condition in application to chirp sounds

It is assumed that for a certain class of sounds there exists a relationship between their pitch and their complex dynamic representation - CDR (real-valued log-envelope and instantaneous angular frequency). The CDR processing appears a powerful means for pitch shifting of chirp-like sound signals fulfilling practically the assumption of the Bedrosian theorem. Scaling the CDR components can be used for entertainment as well as, e.g., in a generator of different melodies for calling signals, where the sound of each note in a melody is derived from a short recording of a voice of a chosen creature. For this aim in this paper a concept of a Bedrosian chirp is proposed whose local instantaneous amplitude and instantaneous complex phasor spectra are separated. A quantitative measure to estimate and predict the quality of sound processing using the CDR scaling is defined and its utility verified on the basis of experiments with real-life audio chirps.