ex_sprec.m
contains a more elaborate example of the use of
H2M functions for an isolated words speaker-dependent recognition task
(with no recording variability). I included this example because it provided a
simple way of answering most of the question I was asked concerning H2M (please, don't ask me about speech recognition anymore!). I do however
insist on the following: (1) ex_sprec.m
is not meant to be used for
real-world speech recognition (see section 2.5.3 on computation
time and memory usage), (2) I am not a speech recognition expert and thus
cannot answer questions concerning this particular use of H2M functions.
This is a very simplistic example where basic models (left-right models with five states and a single shared covariance matrix) are sufficient to get rid of all errors on a small size training set (which is again not at all typical of real-world speech recognition applications). The code is commented so that it should not be too difficult to figure out what's going on.
If you run into trouble, it will probably happens when reading the signal file
data/
digits.sig
which is a binary file contains shorts (16 bits
signed integers) recorded on a little-endian system (PCs running Windows
or Linux are typically little-endian systems, most Unix workstations are
big-endian). I have successfully run ex_sprec
on various Unix systems
(little and big-endian) using either MATLAB V5 or OCTAVE 2.0, so I hope
to have cleared all the input/output problems. The script tries to determine
which of MATLAB or OCTAVE is used so as to add the octave
subdirectory
to the search path if needed.
Running ex_sprec
requires about 6 Mb of memory, or 15 Mb if you have to
overwrite the signal file (which is my own stupid way of coping with old
versions of MATLAB or OCTAVE running on big-endian systems). On my own Linux
box (Pentium III - 1 GHz hardarwe), the computation time for ex_sprec
(parameterization, training and recognition) ranges from 48.5 s under OCTAVE to
9.1 s using MATLAB with all computational routines compiled.
Olivier Cappé, Aug 24 2001