15. The method of claim 13 , wherein the post-processing function comprises the addition of certain nonspecific frequency components into each of the frequency domain representations.
13. A computer-implemented method for anonymizing speech data, the method comprising: receiving a raw audio waveform containing speech data of a user; segmenting the raw audio waveform into a plurality of intervals; generating a frequency domain representation of each interval; applying a post-processing function to smooth each frequency domain representation and remove at least a portion of speaker-identifying data from each frequency domain representation; identifying a frequency component in one of the plurality of intervals that represents a spoken word in the raw audio waveform and cannot be used to identify the user; extracting the frequency component from the corresponding interval; providing metadata and the frequency component to an analysis system for processing, where the metadata identifies the speaker-identifying data removed from each frequency domain representation by the post-processing function; receiving, from the analysis system, processed data; and determining, for a synthetic character, an appropriate emotional state or responsive action based at least in part on the processed data.