I try to transfer the sound of 1,000 Hz from FreeSwitch to the browser and watch the quality of the sound, depending on the client type. Especially for this experiment, I created an external sip-profile: <gateway name="sip2sip.info"> <param name="username" value="soundtest"/> . . . </gateway> and following dialplan: <include> <extension name="soundtest@sip2sip.info"> <condition field="destination_number" expression="^soundtest$"> <action application="gentones" data="%(3500,0,1000)|-1"/> </condition> </extension> <extension name="mod_rtmp"> <condition field="source" expression="^mod_rtmp$"> <action application="gentones" data="%(3500,0,1000)|-1"/> </condition> </extension> </include> And reproducing clients: http://call2sip.ru - created on the basis of SIPml-api (correct work only under the Chrom) and http://soundtest.iiiii.info - created on the basis of mod_rtmp flex- client side Sound is produced as a result of the test recorded on the mic. At first, made the call from the SIPml-client to the number soundtest@sip2sip.info and recorded the resulting sound. Then made a call from the flex-client (in which case the destination number does not matter) and also recorded the resulting sound. Both sound recorded in a single file. Here's a link to this file: http://cs536109v4.vk.me/u78896495/audios/0efae0afdb31.mp3 As you can see this, copies of the same signal are quite different in quality. In other words, the sound reproduced through the flex contains a very noticeable defects. But it is only in the case where the sound is played in Windows 7. About other systems say anything until I can not. In this Friswitch was running on a remote server on CentOS 6.3. Yet I performed the same test when Friswitch was launched in the same system that plays sound. In this case, 50% of attempts were given a faulty sound, and the remaining 50% were given a normal tone. I also tried to listen to the audio tone through this service: http://s.phono.com/releases/1.1/samples/kitchen-sink/www/index.html And he also got a lot of noise. I would like to know whether it is possible to somehow get rid of this noise? Not giving up the use of flex-technology.