Procmailrc to play sound async when message arrives

[tb.nospam@comcast.net]

I'm a procmail newb.  I've written a recipie to play a WAV when a 
message arrives.  It works, it sounds nice, but it's synchronous:

:0 c
* ^X-Mailing-List:.*lists.debian.org*
| /usr/bin/bplay /x/x/click_x.wav

Since this WAV takes ~1 sec to play, procmail blocks 1 sec per message.  
It ends up taking a long time with a bunch of messages.

Is there any way I can make the clicks "overlap" with multiple messages 
(cl-cl-cl-cl-click vs click.pause.click.pause.click.pause.click) and the 
whole process to run asynchronously to procmail?

Thanks
-Tom