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| Section 4
Noise Gate
Enables or disables a noise gate applied to the caller audio. This is a “downward expander” that has the
effect of reducing the noise on the caller audio when it falls below a threshold. On some very low-level calls,
this attenuation may be inappropriate because you may be able to hear the caller fade away when the level
falls below the threshold. It has three settings as follows:
♦
Off
– Disables the noise gate
♦
Normal
– A slow setting, with moderate noise attenuation
♦
Aggressive
– A faster setting with deeper attenuation, for lines where noise is noticeable during
normal conversation.
Receive EQ (Caller Dynamic Digital EQ – DDEQ)
Telephone audio frequency response varies widely since many factors can affect it (we’ve measured the
response on a number of calls and the results were revealing). Consequently, some form of receive equaliza-
tion is desirable. There are three choices for the type of equalization applied to the received telephone audio:
♦
Off
– The caller audio is passed through without modification. The Rcv EQ values are
ignored in this mode.
♦
Fixed
– This is a simple manual equalizer mode where a fixed EQ is applied.
♦
Adaptive
– This is a three band dynamic equalizer. We’ve chosen frequency breakpoints, time
constants, and other characteristics to optimize the tonal quality of varied telephone callers. The
Digital Dynamic EQ system customizes the callers’ spectral characteristics, which are maintained
from call to call.
♦
Ad Fixed
– This mode separately adds a fixed amount of additional gain to the high and low
frequency bands of the three band Digital Dynamic Equalizer.
(Additional) Low EQ
Amount of low frequency boost or cut applied to the caller audio. Settings are in 2dB steps from 0dB to +6dB
are possible with 0dB representing flat response. The default value is +4dB, which sounds good across a
variety of callers, lines, and telephone sets.
(Additional) High EQ High
Amount of high frequency boost or cut applied to the caller audio. Settings from 0dB to +6dB are possible
with 0dB representing flat response. The default value is 0dB.
Diagnostic Test Mode
Should always remain at “Off” unless instructed to be changed by Telos support.
