found sound from headset and normal speaker

[aiyan11]

i was playing with the snd.force_headset=1, to see if i can get my headset to work with the usb to 3.5mm adaptor and this normally kills all other external sounds. however today i installed whatsapp, and i got a msg and the sound played through the phone's normal speaker. I disconnected the adaptor and everytime i get a msg on whatsapp the sound comes out of the normal speaker. however when i try to play a song there is no sound. this only occurs with whatsapp.

i found this interesting so i would share and see if anyone else gets similar results