Toshiba V.92 - Manual (Page 60)

60 AT Commands
AT command formats
5.375 x 8.375 ver 2.4.0
Ln Monitor speaker volume
This command sets speaker volume to low, medium, or high.
Result Codes:
Mn Monitor speaker mode
This command turns the speaker on or off.
Result Codes:
L0 Low volume
L1 Low volume (Same as L0)
L2 Medium volume (default)
L3 High volume
OK n=0,1,2,3
ERROR Otherwise
M0 The speaker is off.
M1 The speaker is on until the modem detects the
carrier signal (default).
M2 The speaker is always on when modem is off-
hook.
M3 The speaker is on until the carrier is detected,
except when dialing.
OK n=0,1,2,3
ERROR Otherwise