Chapter 8: Applications

Much of the speech and voice technology depends on some type of parameterization of speech and voice. Non-parametric methods, such as the pitchsynchronous overlap add technique (PSOLA) [9, 65, 66], which works in time domain, can only make very limited modifications to the natural speech, with applications confined in, for example, unit-selection TTS systems. To date, the most widely used parameterization methods are linear predictive coding (LPC) [58] and mel-frequency cepstral coefficients (MFCC) [24]. It is known that the vocoders based on LPC and MFCC can only produce reconstructed speech of rather poor quality, for example, see Chapter D24 of Springer Handbook of Speech Processing [6].