You could just mute all DOSBox sounds from windows volume control.

Or, mute the audio in DOSBox by using the mixer, or disabling the various emulated sound boards.

First of all, Thank You for your fast replies, I really appreciate it.

As I want to listen to something else while playing, I cannot turn off the sounds from Windows.

In the options file, there is a header called [mixer], and if I understand this correctly, it says nosound=false

By now you probably notice that I am not too good with this part of computers, so I would appreciate if someone explains to me non-specialist, HOW and WHERE to change the false (I suppose) to true?

Thanks

In the options file, where it says the "nosound=false" you can just change false to true, so it says "nosound=true" and just save the file after that. Also, on windows you can open the start menu, type sndvol on the run/search box, windows then opens a mixer app that you can use to configure the sound for all programs separately.

nosound=true
...should do it. Alternately you can disable the individual emulated sound cards. For Ms PacMan I'm guessing...
sbtype=none
...will do it, though you may need...
pcspeaker=false
...as well.

Thank You very much, everything works perfectly now. I simply changed the options file.

Thanks again for DOS Box, too. I used to play games in arcades in the 80s and I like playing them again occasionally, but the sound is just too hard to take at my age.

Take care of yourself everybody and enjoy life.