ISCA Archive Interspeech 2014
ISCA Archive Interspeech 2014

GMM-based bandwidth extension using sub-band basis spectrum model

Yamato Ohtani, Masatsune Tamura, Masahiro Morita, Masami Akamine

This paper describes a novel GMM-based bandwidth extension (BWE) method based on a sub-band basis spectrum model (SBM), in which each dimensional component represents a specific acoustic space in the frequency domain. The proposed method can achieve the BWE from a speech data with an arbitrary frequency bandwidth while the conventional methods perform the conversion from a fixed narrowband data. In the proposed method, we train a GMM with SBM parameters extracted from wideband spectra in advance. An input signal with a limited frequency band is converted into a wideband signal by estimating high-band SBM components from low-band SBM components of the input signal based on the GMM. The results of some objective and subjective evaluations show that the proposed method extends bandwidth of speech data robustly.