If you're not hearing audio from the headset on a Bluetooth device, try the following:

• Make sure you've set the switch to the Bluetooth icon.
• If you have paired multiple Bluetooth devices with the headset, make sure you're connected to the correct Bluetooth device (see answer 360023404773 for help).
• Connect the headset to a USB port with the charging cable — it may not have enough battery power.
• If you're connected to a computer, make sure you have the Wireless Headset H800 selected as the audio output device (see your computer's documentation for help).
• Make sure the application you're using is configured to use the headset as its audio output device.
• Try disabling other Bluetooth devices.