Pitch detector that makes voiced/unvoiced (v/uv) decision of input speech and determines pitch period of voiced speech is an essential and important device in speech processing systems.
In this thesis a performance comparison study of several pitch detection algorithms for noisy as well as clean speech has been done. To do the comparative study, a data base of six sentences spoken by a male and a female has been prepared, and their pitch periods and v/uv decisions were determined for reference data by the eye detection method. The algorithms detect pitch periods and v/uv decisions were compared with those reference data. The performance criteria of each algorithm are the number of voiced decision errors, unvoiced decision errors and pitch errors.
In addition, based on the results of the performance comparison, a new algorithm that has been improved from the autocorrelation method with center clipping has been developed. This new pitch detector yields better performance than others so far proposed.
음성 신호에서 유성음과 무성음을 판별하고 유성음내에서 음성 주기를 찾아내는 음성 주기 추출기 ( pitch detector ) 는 음성처리 장비중 기본적이고도 중요한 장치의 하나이다.
본 논문에서는 몇 개의 음성 주기 추출 방법에 대해 잡음이 섞인 음성에서의 동작 성능을 비교 연구하여 보았다. 그리고 이 성능 비교 연구 결과를 토대로 잡음이 섞인 음성에서도 비교적 정확한 동작을 하는 center clipping을 이용한 autocorrelation 방법을 개선시켜 새로운 음성 주기 추출 방법을 제시하였다.
