TR2007-058
| Bandwidth Expansion with a Polya Urn Model | |||
| Citation: | Raj, B.; Singh, R.; Shashanka, M.; Smaragdis, P., "Bandwidth Expansion with a Polya URN Model", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Vol. 4, pp. IV 597 - IV 600, April 2007 (IEEE Explore) | ||
| Date: | April 2007 | ||
| MERL Contact: | Bhiksha Raj | ||
We present a new statistical technique for the estimation of the high frequency components (4-8kHz) of speech signals from narrow-band (0-4 kHz) signals. The magnitude spectra of broadband speech are modeled as the outcome of a Polya Urn process, that represents the spectra as the histogram of the outcome of several draws from a mixture multinomial distribution over frequency indices. The multinomial distributions that compose this process are learnt from a corpus of broadband (0-8kHz) speech. To estimate high-frequency components of narrow-band speech, its spectra are also modeled as the outcome of draws from a mixture-multinomial process that is composed of the learnt multinomials, where the counts of the indices of higher frequencies have been obscured. The obscured high-frequency components are then estimated as the expected number of draws of their indices from the mixture-multinomial. Experiments conducted on bandlimited signals derived from the WSJ corpus show that the proposed procedure is able to aaccurately estimate the high frequency components of these signals. | |||
| |||
