The HTK HMM Toolkit
Phil Woodland, Gunnar Evermann, Steve Young
HTK is a portable toolkit for building and manipulating hidden
Markov models. HTK is primarily used for speech recognition
research although it has been used for numerous other applications
including research into speech synthesis, handwriting recognition
and DNA sequencing. HTK is in use at hundreds of sites worldwide.
It is now available for free
download.
HTK consists of a set of library modules and tools available in C
source form. The tools provide sophisticated facilities for speech
analysis, HMM training, testing and results analysis. The software
supports HMMs using both continuous density mixture Gaussians and
discrete distributions and can be used to build complex HMM
systems. The HTK release contains extensive documentation and
examples.
HTK was originally developed at CUED by Steve Young and Phil
Woodland and it has been used as a basis for CUED's HMM-based
large vocabulary speech recognition systems. In 1993 Entropic
Research Laboratory Inc. acquired the rights to sell HTK and the
development of HTK was fully transferred to Entropic in 1995 when
the Entropic Cambridge Research Laboratory Ltd was established.
HTK was sold by Entropic until 1999 when Microsoft bought
Entropic. Microsoft has now licensed HTK back to CUED and is
providing support so that CUED can distribute HTK and provide
development support via the HTK3
web site.
The initial HTK3 release is closely based on the final Entropic
release, but in future we are intending to integrate into HTK3 a
number of the features that have been used at CUED in research
systems and provide infrastructure for speech recognition research
such as word lattices for standard tasks.
htk-mgr@eng.cam.ac.uk
Last modified: Tue Sep 26 19:30:25 BST 2000