Toyota 2009 Yaris Hatchback Owner's Manual page 220

3-2. Using the audio system
Adjusting the Automatic Sound Levelizer (ASL)
n
When "ASL" is selected, turning
"ASL level in the order of the "LOW", "MID" and "HIGH".
Turning
ASL automatically adjusts the volume and tone quality according
to the vehicle speed.
Trademark owned by SRS Labs, Inc.
n
The audio system utilizes SRS FOCUS
enhancement technologies, under license from SRS Labs, Inc., in all modes
except AM radio mode.
FOCUS, TruBass, SRS and
Inc. FOCUS and TruBass technologies are incorporated under license from
SRS Labs, Inc.
208
to the left turns "ASL" off.
symbols are trademarks of SRS Labs,
to the right changes the
®
and SRS TruBass
®
audio