An accurate model for the structure of speech is essential to many speech processing applications, including speech en-hancement, synthesis, recognition, and coding. This paper ex-plores some deficiencies of standard harmonic methods of mod-eling voiced speech. In particular, they ignore the effect of fun-damental frequency changing within an analysis frame, and the fact that the fundamental frequency is not a continuously vary-ing parameter, but a side effect of a series of discrete events. We present an alternative, time-series based framework for modeling the voicing structure of speech called the fine pitch model. By precisely modeling the voicing structure, it can more accurately account for the content in a voiced speech segment. Index Terms: speech analysis, pitch estimation, fundamental