You cannot hear the sound even if a Bluetooth connection has been made.

• The volume of the connected Bluetooth device is muted.

• Unmute the connected Bluetooth device.

• The volume is set to zero.

• It may not be possible to adjust the volume of certain connected Bluetooth devices. Turn up the volume on the Bluetooth device or your Walkman.

• Playback of the file has not started.

• Start playing back the file on your Walkman.

• The connected Bluetooth device is not turned on.

• Turn on the connected Bluetooth device and make sure the Bluetooth function is activated.

• Bluetooth connection was severed.

• Establish a Bluetooth connection. [Details]

• The profile of the connected Bluetooth audio devices does not support AVRCP.

• Make operations on your Walkman.