Systems, methods and apparatus for determining an estimated endpoint of human speech in a sound wave received by a mobile device having a speech encoder for encoding the sound wave to produce an encoded representation of the sound wave. The estimated endpoint may be determined by analyzing information available from the speech encoder, without analyzing the sound wave directly and without producing a decoded representation of the sound wave. The encoded representation of the sound wave may be transmitted to a remote server for speech recognition processing, along with an indication of the estimated endpoint.