You may experience problems with the sound while using the Vive’s headphone extension cable. IF you do so, this tutorial will guide you how to successfully solve this problem. Follow this steps:
Step 1. Wake up the headset from the standby mode
■ Just move your headset
■ Go to SteamVR Audio Settings. Check if they are sending audio to the Vive.
■ SteamVR > Settings > Audio > Set Playback Device > Choose HTC –VIVE or select the Speakers.
Step 3. Check if Windows is sending audio to the HTC-VIVE-O audio device.
■ Open Windows > make a right click on the Volume icon in task tray > select Playback devices > select HTC Vive-O
■ Make a right click on the HTC Vive-O > select Set as Default Device
■ You may also need to make a right click on some audio device and choose Show Disabled Devices and Show Disconnected Devices.
■ Open Volume Icon > set the volume slider to 50 %
■ Check the volume of programing playing audio
■ Volume Icon > Mixer > set the volume slider at least 50%
■ Open Windows > Volume Icon > Right Click on Speakers 2-USB Audio Device > choose Set as Default Device.
■ You may need to use the USB extension cable.