If there is no sound coming from an external device connected to your VAIO computer, you need to change the device for sound output.
If there is no check mark next to the icon, select it and Set Default.
The sound rate and bit depth of the digital audio output signal should be set according to your digital audio device.
Follow the above steps 1 to 3, and then select the HDMI device or OPTICAL OUT (optical digital audio output) icon and Properties. On the Advanced tab, select the sample rate and bit depth (for example, 16 bit, 48000 Hz (DVD quality)) which the device supports, and then OK.