Playback sound is messed up ( crippled )

Hi, I try to learn playback feature.
exten => 5,2,Playback(/usr/share/asterisk/sounds/hello-world)

I installed asterisk from Ubuntu packages ( sudo apt-get install asterisk ).

The version?
hulahula*CLI> show version
Asterisk built by buildd @ terranova on a i686 running Linux on 2006-08-04 06:49:36 UTC

This is my sip.conf:

videosupport=yes		; Turn on support for SIP video
disallow=all			; First disallow all codecs
allow=ulaw			; Allow codecs in order of preference
qualify=yes      ; Qualify peer is no more than 2000 ms away
nat=no           ; This phone is not natted
host=dynamic     ; This device registers with us
canreinvite=no   ; Asterisk by default tries to redirect
context=internal ; the internal context controls what we can do

This is my extensions.conf

exten => 5,1,Answer()
exten => 5,2,Playback(/usr/share/asterisk/sounds/hello-world)
exten => 5,3,Hangup()

I run asterisk server and client in local lan.
Ok, I test it with yate softphone:
When I click 5 and dial it, it connects and I can hear the sound but it is messed up. I didn’t know what it say. The sound came very quickly. But the volume is okay. The sound is quite loud.

I got this in my asterisk console ( in server ):
– Executing Answer(“SIP/john-ac53”, “”) in new stack
– Executing Playback(“SIP/john-ac53”, “/usr/share/asterisk/sounds/hello-world”) in new stack
– Playing ‘/usr/share/asterisk/sounds/hello-world’ (language ‘en’)

Ok, what’s wrong? Oh yeah any software to listen gsm file in linux? I just curious what hello-world.gsm sounds like.

I don’t know why the playback is clumsy. But, you can use “Play” utility in linux for playing gsm,wav files etc… It comes along with standard sox package.