User Guide

466 Chapter 2: ActionScript Language Reference
Microphone.setUseEchoSuppression()
Availability
Flash Player 6.
Usage
active_mic.setUseEchoSuppression(suppress:Boolean) : Void
Parameters
suppress
A Boolean value indicating whether echo suppression should be used (true) or
not (
false).
Returns
Nothing.
Description
Method; specifies whether to use the echo suppression feature of the audio codec. The default
value is
false unless the user has selected Reduce Echo in the Flash Player Microphone
Settings panel.
Echo suppression is an effort to reduce the effects of audio feedback, which is caused when sound
going out the speaker is picked up by the microphone on the same computer. (This is different
from echo cancellation, which completely removes the feedback.)
Generally, echo suppression is advisable when the sound being captured is played through
speakers—instead of a headset—on the same computer. If your SWF file allows users to specify
the sound output device, you may want to call
Microphone.setUseEchoSuppression(true) if
they indicate they are using speakers and will be using the microphone as well.
Users can also adjust these settings in the Flash Player Microphone Settings panel.
Example
The following example turns on echo suppression if the user selects a CheckBox instance called
useEchoSuppression_ch. The ProgressBar instance called activityLevel_pb displays the
current activity level of the audio stream.
var useEchoSuppression_ch:mx.controls.CheckBox;
var activityLevel_pb:mx.controls.ProgressBar;
this.createEmptyMovieClip("sound_mc", this.getNextHighestDepth());
var active_mic:Microphone = Microphone.get();
sound_mc.attachAudio(active_mic);
activityLevel_pb.mode = "manual";
activityLevel_pb.label = "Activity Level: %3";
useEchoSuppression_ch.selected = active_mic.useEchoSuppression;
this.onEnterFrame = function() {
activityLevel_pb.setProgress(active_mic.activityLevel, 100);
};
var chListener:Object = new Object();
chListener.click = function(evt:Object) {