1. A computer-implemented method for non-intrusive speech quality detection without a reference signal comprising: receiving, at a computing device configured to convert voicemail to text, a first speech signal associated with a user; extracting one or more short-term features from the first speech signal wherein extracting short-term features includes extracting a time frame of between 10-50 ms, wherein the one or more short term features include a Hilbert envelope based feature and a linear predictive coding residual; determining one or more statistics of each of the one or more short-term features from the first speech signal; classifying the one or more statistics as belonging to one of a set of quality classes, wherein classifying the one or more statistics includes modeling a speech quality class using a binary tree classifier; and automatically generating at least one training database, based upon, at least in part, the first speech signal and an intrusive speech quality algorithm, wherein the intrusive speech quality algorithm is not used during the receiving, extracting, determining, and classifying operations.