1. A method for determining speech quality comprising: receiving a first signal and a second signal, wherein the second signal is a degraded version of the first signal; creating a time-frequency representation for each of the two signals; using the time-frequency representation for the first signal to select at least one portion of the first signal containing speech data; identifying, based on time-frequency representation for the second signal, at least one portion of the second signal corresponding to the at least one portion of the first signal; determining a level of similarity between the second signal and the first signal based on a comparison of the at least one portion of the second signal and the corresponding at least one portion of the first signal, wherein the level of similarity is determined using Neurogram Similarity Index Measure (NSIM); and generating a speech quality estimate based on the level of similarity determined using NSIM.