Skip to main content


Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: Transform Coders and speech / vocal like signals (Read 2484 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Transform Coders and speech / vocal like signals

I understand that most psychoacoustic based transform coders have difficulties in
coding signals like speech or music clips with strong vocals..  From my listening tests.. I find that these clips seemed to lose some of its "original" quality..

One possible explanation has something to do with the mis-match between the masking threshold calculated in long block for a signal that changes rapidly in time.. and switching to short blocks isn't a good solution as it involves too much block switching..  In AAC there is the TNS tool which flattens the temporal envelope and provides a better matching between the masking thresh and the quantization noise..

Still it is NOT good enough.. The vocals sounded a little flat.. sometimes like someone singing with a "nose block"!! Pitch related problem ??

I wondered if the LTP tools will provide an even better modelling of these kind of signals..