Turn off Dialer sound/Instant End

[BOO B)]

Here is the hack to change end key time:
This edit will change the time between pressing the "End Key" and actually ending the call. It is originally 3 seconds, and you can change it to any number, including 0 for NO DELAY
HKLM\Software\HTC\PHONE
“PhoneExtendSetting” <<-- YOU WILL HAVE TO ADD THIS KEY
ADD the dword “EndCallTime” and make the value 1000 (one second) or 0 (no delay)