Patent ID: 9160843
Filing Date: 2015-10-13
Classification: G10L,H04M

Abstract:
1. A method of processing a speech signal, the method comprising: receiving the speech signal at a communication client running on a receiving terminal, the receiving terminal connected to a packet switched network, the speech signal originating at a telephone device coupled to a circuit switched network, the circuit switched network and the packet switched network coupled via a gateway, wherein frequency components in the received speech signal are limited to a predetermined frequency range and the received speech signal has been filtered by the telephone device using a transmitter frequency response over the predetermined frequency range; the communication client decoding the received speech signal and making a determination regarding whether the telephone device is a terminal in the circuit switched network or the packet switched network; and responsive to determining that the telephone device is a terminal in the circuit switched network, filtering, by the communication client, the decoded speech signal using a receiver frequency response which is complementary to the transmitter frequency response over the predetermined frequency range to thereby reduce distortion in the speech signal by adapting the speech signal to a target power spectrum derived from long-term averaging of voiced speech signals.