Next: Speaking aspects
Up: Speech recognition systems
Previous: Speaker dependency
The system may incorporate a speaker adaptation procedure that allows the system
to learn the current
speaker characteristics and thus improve its performance during the interaction. At the beginning the
system may be used in a degraded mode (either speaker-independent or speaker
on another speaker) and ending up as an optimised speaker-adapted system.
The adaptation may have to be done by the application developer
in order to tune the system to his
specific application. Usually two approaches are used:
- A static adaptation process:
One has to start from an off-line recording of data and a
training phase before using the system. The system references are adapted to the new
speaker once and for all. The duration of this process is important: it can be
real-time or even last for hours. The speech data needed can be acoustic data without any manual labelling or
manual pre-processing , or it may have to be labelled (orthographic plus phonetic). The
speech corpus may range from a few minutes of speech to a few hours.
- A dynamic adaptation process:
The system learns the current speaker characteristics while the speaker
is using the system. This may be done by user request if errors occurred
during the application, or the system may automatically take into consideration
the speech data uttered by the present speaker.
If this procedure is available the application developer has to know how to
use it and he needs the know-how to collect and process the required data.
EAGLES SWLG SoftEdition, May 1997. Get the book...