It is easy to mute all system sounds. However there is no button to mute only the plugged-in sounds. For example, there is a button for muting keyboards clicks and another button for muting locking/unlocking sounds. If you wanted to mute the sounds when plugging in, you would have to mute all system sounds. Although you should be able to listen to music and watch videos, I have noticed that when I watch some youtube videos with the sound muted, I cannot hear them. This isn't like this for all youtube videos, but for some it happens. If you watch lots of youtube videos, I wouldn't recommend muting it, and just getting used to the sound. If you don't watch youtube videos and do not use the sound a lot, it would be better for you to mute it. Once again, it depends in you.
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