DELTA COEFFICIENTS
- Temporal variation is modeled with time derivatives, or
delta features:
![](./../images/eqn13.gif)
- A regression model leads to better recognition performance:
![](./../images/eqn14.gif)
- The delta window parameter
is set by the
user. A high value brings in more longer term information, but adds
latency.
- Differential features improve WER on SWITCHBOARD
by 5%.