Polycom SOUNDPOINT SIP 2.2.0 - Manual (Page 154)

Administrator’s Guide SoundPoint IP / SoundStation IP
A - 42
Background Noise Suppression <ns/>
These settings control the performance of the transmit background noise
suppression feature.
Polycom recommends that you do not change these values.
Attribute Default
voice.ns.hs.enable 0
voice.ns.hs.signalAttn -6
voice.ns.hs.silenceAttn -9
voice.ns.hd.enable 0
voice.ns.hd.signalAttn 0
voice.ns.hd.silenceAttn 0
voice.ns.hf.enable 1
voice.ns.hf.signalAttn -6
voice.ns.hf.silenceAttn -9
voice.ns.hf.IP_4000.enable 1
voice.ns.hf.IP_4000.signalAttn -6
voice.ns.hf.IP_4000.silenceAttn -9