User Manual

■ “Mic” screen
When using a mic equipped with a PTT (Push To Talk) switch, a small amount of noise may be heard while the
PTT switch is off. If this noise is input to the AEC, the AEC will mistakenly learn the noise, causing an echo when
the PTT switch is turned on to resume speaking. In this screen you can make settings and specify the type of
mic to prevent this from occurring.
① PTT[ON] button
If this is on, and the input level from the local mic (Near-end Mic) falls below the value specified in PTT
Threshold, the system will determine that the PTT switch of the local mic has been turned off, and will stop AEC
learning. We recommend
that you leave this on.
② Mic In. meter
This indicates the level of the signal that is input from the local mic (Near-end Mic). This meter will also indicate
the level of the noise that occurs when the PTT button of the mic is off.
③ [PTT Threshold] knob
This knob sets the reference level for AEC learning. If the PTT [ON] button is on, AEC learning will stop when the
input signal to the local mic (Near-end Mic) falls below this level; learning will resume when the input signal
exceeds this level.
The Mic In. meter indicates the level of the input signal.
④ [Mic. Type] list box
Specify the type of mic that is connected.
Choose “Fixed” for an environment in which the distance between the mic and speaker is fixed, or “Moving” for
an environment in which this distance changes, such as when a hand mic is used. Even in an environment in
which the distance between the mic and speaker is fixed, choose “Moving” if the echo is obtrusive.
14. Audio Processors : MTX5-D/MTX3
220 | ProVisionaire Design User Guide