Hello , I recommend you to first change your broadcasting software to see if there are any differences, I mean if you get sound.

Personnaly I work for a company offering BlinkoTv. The broadcaster gives you the option to change the broadcasting settings like bitrate, deinterlacing method, fps, the audio source.
Try getting this and let me know if you encounter problems. For me it s working and I am using a Vixia HF10 camera model as video source (i have audio also).