Privacy Preserving Speech Processing

Speech is one of the most private forms of communication. People do not like to be eavesdropped on. They will frequently even object to being recorded; in fact in many places it is illegal to record people speaking in public, even when it is acceptable to capture their images on video [1]. Yet, when a person uses a speech-based service such as a voice authentication system or a speech recognition service, they must grant the service complete access to their voice recordings. This exposes the user to abuse, with security, privacy and economic implications. For instance, the service could extract information such as gender, ethnicity, and even the emotional state of the user from the recording factors not intended to be exposed by the user and use them for undesired purposes. The recordings may be edited to create fake recordings that the user never spoke, or to impersonate them for other services. Even derivatives from the voice are risky to expose. E.g. a voice-authentication service could make unauthorized use of the models or voice prints it has for users to try to identify their presence in other media such as YouTube. This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. Copyright c © Mitsubishi Electric Research Laboratories, Inc., 2013 201 Broadway, Cambridge, Massachusetts 02139