Sound not working with HDMI

I'm trying to watch a movie in my Inspiron 13 with Windows 10, using an HDMI cable to send the image to my TV, and a normal audio cable to send the sound to a Receiver. I can use this setup with my phone and iPad, and thought it was going to be just plug and play, but when I connect the HDMI cable, the sound stops working. 

I'm guessing it is trying to send both sound and image through the HDMI cable, but we don't use the speakers in the TV, so I'm not sure how to fix that. Any ideas?

Thanks!

Lucas