Shrikanth S Narayanan
Articles written in Sadhana
Volume 36 Issue 5 October 2011 pp 699-712
The transmitter and the receiver in a communication system have to be designed optimally with respect to one another to ensure reliable and efﬁcient communication. Following this principle, we derive an optimal ﬁlterbank for processing speech signal in the listener’s auditory system (receiver), so that maximum information about the talker’s (transmitter) message can be obtained from the ﬁlterbank output, leading to efﬁcient communication between the talker and the listener. We consider speech data of 45 talkers from three different languages for designing optimal ﬁlterbanks separately for each of them. We ﬁnd that the computationally derived optimal ﬁlterbanks are similar to the empirically established auditory (cochlear) ﬁlterbank in the human ear. We also ﬁnd that the output of the empirically established auditory ﬁlterbank provides more than 90% of the maximum information about the talker’s message provided by the output of the optimal ﬁlterbank. Our experimental ﬁndings suggest that the auditory ﬁlterbank in human ear functions as a near-optimal speech processor for achieving efﬁcient speech communication between humans.