Sony PSP-1006 K - Manual (Page 34)

34 Using the sound button
The sound button is used to adjust the tone and to mute the sound for audio
playback and for key tones.
1
Press the sound button.
Each time you press the button, the tone changes as follows:
Hint
Tone can only be adjusted when using the headphones. Also, note that the tone setting is
temporarily set to "OFF" during gameplay.
1
Hold down the sound button for more than one second.
The sound will be muted.
Using the sound button
Adjusting the tone
HEAVY Strengthens both bass and treble to produce an intense sound
POPS Strengthens the mid-range. Ideal for vocals
JAZZ Strengthens both bass and treble to produce a balanced sound
UNIQUE Strengthens bass, treble and mid-range sound
OFF Normal tone
Turning off the sound (mute)
POWER
HOLD
SELECT START