Macromedia flash media server 2-developing media applications User Manual

Page of 114
48
Using Media Classes
The Microphone class
This section includes recommendations for optimizing your use of the Microphone class, 
including tips on avoiding audio feedback. 
Avoiding audio feedback 
If you’re using a microphone with external speakers and a reasonably high gain, you’re likely to 
incur audio feedback problems. To reduce feedback from speakers, Flash Media Server uses 
echo suppression, which you can implement by using the following command:
my_mic.useEchoSuppression(true); 
This should maintain a comfortable input level without transmitting too much echo from 
your speakers. 
Because echo suppression removes only a portion of the output signal from the user’s input, 
you might still experience feedback if your microphone is too close to your speaker. To avoid 
feedback, try following these guidelines:
Lower your speaker volume. 
Move the microphone and speakers farther apart.
Troubleshoot your hardware setup for proper installation and settings.
Use a headset.
Keeping the microphone on
To save bandwidth, Flash Media Server by default turns off the microphone when it is not 
being used. However, you might want to keep it on in your application—for example, to 
ensure that there is no delay when the microphone is activated. To keep the microphone on, 
use the following command:
my_mic.setSilenceLevel(0).