I've searched through the forum on this but didn't see this addressed. I have a TCH base model and on page 185 of the manual it states the following:

"Switching over the Speed Automatic Sound Levelizer (ASL) level
ASL: The Automatic Sound Levelizer can be turned on by turning the knob. In addition, turning the knob allows you to select from LOW, MID, and HIGH volume and tone settings."

What does the LOW, MID, and HIGH part mean? I don't see anything like that in the AUDIO CNTL options.