Speaker adaptation in a phonetic vocoding environment

The coder proposed in this paper falls in the class of segmental vocoders known as phonetic vocoders. Speaker recognisability is one of the main problems faced by vocoders at the lowest bit rates, given the need to reduce speaker specific information. Hence, phonetic vocoders are very suitable to speaker dependent coding, and can achieve bit rates as low as 250 bit/s. For speaker independent coding a speaker adaptation methodology is adopted, although resulting in higher bit rates to transmit the speaker specific information. In order to further reduce the corresponding bit rate, a new method is proposed that explores the intra-speaker correlation for the same phone.