User guide

Developers guidelines | AT commands
83 June 2010
AT+NREC Noise reduction and echo cancelling
AT+VGM Gain of microphone
Description: Enables/disables any Echo Cancelling and Noise Reduction functions
embedded in the phone.
Note: This command only works over Bluetooth wireless technology. This
is because all AT commands for audio preferences are deleted and
replaced with an audio class and id. However, the command is standard
for the BTHF profile and is therefore used in this context.
Execution
command: AT+NREC=<nrec>
Test command: AT+NREC=? Shows if the command is supported.
Test command
response: +NREC: (list of supported <nrec>s)
Parameter:
<nrec>:
<nrec> Description
0 Disables EC/NR in the phone
1 Enables EC/NR in the phone
Description: Command issued by the HF to report its current microphone gain level set-
ting to the phone. <gain> is a decimal numeric constant, relating to a par-
ticular (implementation dependent) volume level controlled by the HF. This
command does not change the microphone gain of the phone, it simply
indicates the current value of the microphone gain in the HF.
This command activates the result code +VGM
Execution
command: AT+VGM=<gain>
Test command: AT+VGM=? Shows if the command is supported.
Test command
response: +VGM: (list of supported <gain>s)
Parameter:
<gain>:
<gain> Description
0–15 0 – Minimum gain
15 – Maximum gain