Ravi P. Ramachandran

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Line spectral frequencies provide an alternate parameterization of the analysis and synthesis filters used in linear predictive coding (LPC) of speech. In this paper, a new method of converting between the direct form predictor coefficients and line spectral frequencies is presented. ,The system polynomial for the analysis filter is converted to two(More)
The future commercialization of speaker- and speech-recognition technology is impeded by the large degradation in system performance due to environmental differences between training and testing conditions. This is known as the "mismatched condition." Studies have shown [l] that most contemporary systems achieve good recognition performance if the(More)
Speaker recognition refers to the concept of recognizing a speaker by his=her voice or speech samples. Some of the important applications of speaker recognition include customer veri cation for bank transactions, access to bank accounts through telephones, control on the use of credit cards, and for security purposes in the army, navy and airforce. This(More)
The pitch-predictor contributes greatly to the efficiency of current analysis-by-synthesis speech coders by mapping the past reconstructed signal into the present. However, for good performance, it is required that its parameters are updated often (once every 2.5-7.5 ms). A slower update rate of the pitch-predictor delay results in time misalignment between(More)
Cochannel interference of speech signals is a common practical problem particularly in tactical communications. Ideally, separation of the individual speech signals is desired. However, it is known that when two equal bandwidth signals are added, such a separation is not possible. We examine the problem of identifying temporal regions or frames as being(More)