You can hear a slight noise from the TV speakers (only models with TV centre speaker mode).

Models with TV centre speaker mode have a 中置扬声器输入 terminal or S-中置扬声器输入 terminal in the back.

If an AV receiver is not connected to the 中置扬声器输入 terminal on the TV, or if an audio system that supports the S-中置扬声器输入 terminal is not connected, you may hear a slight noise from the TV speakers when [Speakers] is set to [Audio system].

If you are concerned about the noise, disable the following setting:

Press the 主菜单/(HOME) button, then select:
[Settings] — [TV centre speaker mode] in [Display & Sound] — [Audio output].