Manfred R. Schroeder

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We describe in this paper a code-excited linear predictive coder in which the optimum innovation sequence is selected from a code book of stored sequences to optimize a given fidelity criterion. Each sample of the innovation sequence is filtered sequentially through two time-varying linear recursive filters, one with a long-delay (related to pitch period)(More)
(I had completely forgotten I had written this until I found a reference to it in October 2006. I therefore decided to make it available online. This is theresult of scanning+OCR and still incomplete post-editing. A sequel to this paper is: A. Sloman. On designing a visual system (Towards a Gibsonian computational model of vision). Abstract Some unsolved(More)
In this paper we compare four different pitch tracking algorithms - autocorrelation, cepstrum, harmonic product spectrum, and a new method based on the modulation spectrum - and investigate their fitness for noisy environments. From each tracker, possible &#x0192;<inf>0</inf> candidates in every time window are stored over a 10-frame interval, and the best(More)
Speech analysis and synthesis by linear prediction is based on the assumption that the short-time spectral envelope of speech can be represented by a number of poles. An all-pole representation does not provide an accurate description of speech spectra, particularly for nasals and nasalized sounds. This paper presents a method for characterizing speech in(More)
Absrract-A new class of codes for data compression is described that combines permutations with the fast Hadamard transform (FHT). It was invented for digital speech compression 'based on linear predictive coding (LPC), but may be useful for other data compression applications. One particular code with rate 5 is considered: a ldbit code for a block length(More)