You can set the volume.

Disable your voice chat.

But be aware streamers; this will NOT mute your voice on your stream.

Adjusts the voice chat volume for yourself.

If you are streaming, you need to adjust your voice volume separately in your streaming software.

Change the volume of VirtualCast system sound (the sound that plays when you open the menu).

Limit the loudness of sounds other than the voice chat. When the loudness surpasses the set value, the entire volume will be reduced temporarily.

This is useful for preventing the sound blast from the video player and VCI items.

⇒ About Max Volume Limiter

Change the volume of items, including VCIs.

Change the volume of voices other than yours.

Set the volume for Video Player [Studio] items.

This setting is not for the default volume of individual players, but master video volume.
When set to [Mute], you cannot hear a sound from the niconico video player regardless of its volume setting.