This paper proposes an improved method of glottal closure instant detection using linear prediction and standard pitch concept. The main improvements are on its speed of computation and error reduction on position finding for the cases that were not possible or caused many errors using previous methods. Our method can resolve the problems occurring in current methods to some extent. The false location detection rate is reduced to its inherent interpolation capability. Also the amount of computation is reduced. Another benefit from our method is that it does not need additional post processing to find peaks or smoothing of the pitch tracks. All is contained in itself. Also we compared results among three different kinds of linear prediction based pitch detectors.