Protection of Private Information in a Client/Server Automatic Speech Recognition System

A mobile device adapted for automatic speech recognition for protecting private information on the mobile device comprising:

• a speech input for receiving a speech input signal from a user;
• a local ASR arrangement for performing local ASR processing of the speech input signal using identified private information sources on the mobile device;
• wherein if private information is identified in the result of the local ASR processing of the speech input signal, the control unit declassifies the private information;
• and
• a control unit for sending the speech input signal and declassified private information from the identified private information sources to a remote server for ASR processing.

A method for protecting private information on a mobile device during automatic speech recognition, the method comprising:

• performing automatic speech recognition on an unknown speech signal on the mobile device producing a local speech recognition result;
• identifying private information within the local speech recognition result based on a comparison with data within a local data store on the mobile device;
• obscuring private information within the speech signal;
• transmitting the speech signal with the obscured private information to server;
• receiving a remote speech recognition result from the server;
• and
• outputting a combined speech recognition result based upon the local speech recognition result and the remote speech recognition result, wherein the private information is provided in the combined speech recognition result.

A method for protecting private information on a mobile device during automatic speech recognition, the method comprising:

• performing automatic speech recognition on an unknown speech signal on the mobile device producing a local speech recognition result;
• identifying private contact information within the local speech recognition result based on a comparison with a contact list database within a local data store on the mobile device;
• obscuring a first portion of the private contact information within the speech signal;
• transmitting the speech signal with a second portion of the private contact information to a server, wherein the first portion of the private contact information is obscured;
• receiving a remote speech recognition result from the server;
• and
• outputting a combined speech recognition result based upon the local speech recognition result and the remote speech recognition result, wherein the private contact information is provided in the combined speech recognition result.