In speech/music coders and analysis/synthesis systems, spectral modeling is generally performed on a short-term (ST) frame-by-frame basis, which is justified by the fact that the signal is only locally (quasi-) stationary. The vocal tract configuration moves slowly and smoothly thereby resulting in a high correlation between the spectral parameters of successive frames: this correlation property is exploited in long-term modeling of the ST parameters, which however results in longer modeling/coding delays. The short delay constraint can be relaxed in many applications, such as text-to-speech modification/synthesis, telephony surveillance data, digital answering machines, electronic voicemail, digital voice logging, electronic toys, and video games. The long-term harmonic plus noise model (LT-HNM) for speech shows additional data compression possibilities since it exploits the smooth evolution of the time trajectories of the short-term harmonic plus noise model parameters by applying a discrete cosine model (DCM). In this paper, the authors extend the LT-HNM to a complete low bit-rate speech coder that is based on a long-term approach ca. 200ms. The proposed LT-HNM coder reaches a bit-rate of 2.7kbps for wideband speech.
Click to purchase paper as a non-member or you can login as an AES member to see more options.
No AES members have commented on this paper yet.
To be notified of new comments on this paper you can
subscribe to this RSS feed.
Forum users should login to see additional options.
If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.
