You will have to upload a sound clip then when there is any new message you will need to play that sound. That need some custom coding.
I reckon your onto something there. I have a heap of 1.5 second sounds if you want them to incorporate in yr next update
This would be very nice feature. please consider this feature
Shamim Hasan how we going with that ?
If you own that sound and want to contribute, you are welcome. If you are comfortable using github you can use https://github.com/shamim2883/front-end-pm or send to me.