> 18.9 | AT^SNFA Set or query of microphone attenuation

> AT^SNFA specifies the large-scale attenuation on the microphone path of the audio device currently selected with AT^SNFS. The write command is only available in audio modes 2 to 6.
> Syntax

> Test Command AT^SNFA=?
> Response(s)
> ^SNFA: (list of supported <atten>s)
> OK

> Read Command AT^SNFA?
> Response(s)
> ^SNFA: <atten>
> OK

> Write Command AT^SNFA=<atten>
> Response(s)
> OK
> ERROR
> CME ERROR: <err>

> Reference(s) |  | PIN |  | ASC0 | ASC1 | USB | MUX1 | MUX2 | MUX3 |  |  | Charge | Q | Last
> SIEMENS |  | - |  | + | + | + | + | + | + |  |  | - | + | -

> Parameter Description

> <atten>(num)(^SNFW)

> Multiplication factor for input samples. Parameter <atten> is identical with <inCalibrate> of AT^SNFI.
> Formula used to calculate microphone attenuation (negative gain):
> Gain in dB = 20 * log(<atten>/32768)
> 0...32767(P)...65535
> 0
> Microphone is muted.
> Please note that AT^SNFA cannot be used to mute the microphone. Therefore, any attempt to enter 0 will be rejected with error response. Value 0 is returned only by the read command AT^SNFA? after the microphone was muted with AT^SNFM=0 during an active call.
> 32767
> No attenuation on the microphone path
> Values greater than 32767 will be suppressed to 32767.
> Notes

> • | This command is provided for compatibility with former products (e.g. M20) and is a subset of AT^SNFI. The parameter <inCalibrate> of AT^SNFI is identical with <atten> of AT^SNFA.

> • | To make the changes persistent use AT^SNFW.

> Example

> ^SYSSTART
> at^snfa=?
> ^SNFA: (0-65535)
> OK
> at^snfa?
> ^SNFA: 32767
> OK
> at^snfs=4
> OK
> at^snfa=1
> OK
> at^snfa?
> ^SNFA: 1
> OK
> at^snfi?
> ^SNFI: 5,1
> OK
> at^snfi=5,45
> OK
> at^snfa?
> ^SNFA: 45
> OK