By default, when connecting AUX cable to your Xbox remote, the TV speakers will not automatically mute. 

That allows you to connect woojer strap to the Xbox remote control and still listening to the sound from the TV screen. (Make sure your TV volume is not low)

Also you can use an external speakers.

To do so, you will need a 3.5mm splitter, and two aux cables.
Connect the 3.5mm splitter to your remote audio output. 

Connect one AUX cable between the 3.5mm splitter and the Strap audio input.
Connect the second AUX cable between the 3.5mm splitter and the audio input of the speaker/amplifier.

*Important Notes:

1. As some controllers have weak audio amplification, in order to get higher audio and sensation levels you may choose to connect the Strap directly to the TV screen. 

2. Remember to always set your audio source to HIGH volume.