Commands to mute and unmute the speakerphone.
One or more command strings can be used. For example,
HKR, SpeakerPhoneMute, 1,, "at#spk=0,,," HKR, SpeakerPhoneUnMute, 1,, "at#spk=1,,,"
These commands are issued after a call has been connected in voice mode, and speakerphone has been enabled. These commands are sent only after the speaker phone has been enabled, and the TAPI function phoneSetHookSwitch is called with the to change the mute setting.
See also Overview of speakerphone modes in Modem Development Kit documentation.