Polycom SOUNDPOINT SIP 3.1 - Manual (Page 201)

Configuration Files
A - 47
Background Noise Suppression <ns/>
These settings control the performance of the transmit background noise
suppression feature.
voice.aes.hf.duplexBalance.2 6
voice.aes.hf.duplexBalance.3 6
voice.aes.hf.duplexBalance.4 5
voice.aes.hf.duplexBalance.5 4
voice.aes.hf.duplexBalance.6 4
voice.aes.hf.duplexBalance.7 3
voice.aes.hf.duplexBalance.8 2
voice.aes.hf.duplexBalance.IP_4000.0 10
voice.aes.hf.duplexBalance.IP_4000.1 9
voice.aes.hf.duplexBalance.IP_4000.2 8
voice.aes.hf.duplexBalance.IP_4000.3 7
voice.aes.hf.duplexBalance.IP_4000.4 6
voice.aes.hf.duplexBalance.IP_4000.5 5
voice.aes.hf.duplexBalance.IP_4000.6 4
voice.aes.hf.duplexBalance.IP_4000.7 3
voice.aes.hf.duplexBalance.IP_4000.8 2
Attribute Default
Polycom recommends that you do not change these values.
Attribute Default
voice.ns.hs.enable 1
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