Speech envelope estimation and voiceless consonant restoration for artificial bandwidth extension of narrow band speech

In this paper, we propose a new artificial bandwidth extension technique for telephone speech. Usually, the high frequency components of telephone speech are lost due to band limitation. The proposed method produces the high frequency components by estimating the spectral envelope of voiced speech and by restoring voiceless consonant spectrum. Objective evaluations in experiments showed that the proposed method provides better results than the conventional method.