This work presents a method for improving accuracy of Vowel Onset Point (VOP) and Vowel End Point (VEP) detection in continuous speech. VOP and VEP are the instants at which the onset and offset of vowel takes place, respectively, during speech production. Speech signal is represented using Bessel functions with their damped sinusoid-like basis functions. Bessel expansion is used to emphasize the vowel regions by appropriate consideration of the range of Bessel coefficients. Bandpass filtered narrow-band signal is modeled as a monocomponent amplitude modulated-frequency modulated (AM-FM) signal. The amplitude envelope (AE) function of this vowel emphasized AM-FM signal gives strong evidence for the VOP and VEP. This evidence after adding with some of the existing evidences having source and system information, increases the detection rate as well as the accuracy of detection. © 2014 IEEE.