I made many Lumio files years ago for my middle school music classes that had objects with attached sound files. Click on the object and you would hear a note or a chord or an interval, etc. I was originally a Montessori teacher, so my emphasis was always on a simplicity of design - both for aesthetic and instructional purposes. No distracting elements.
I don't remember the Lumio version number I used when I made my Lumio manipulatives, but there were no speaker icons attached to objects that I made with sound files attached. I understand that there was some particular instructional design reason why the speaker icons were added, but as there is also a design reason why one would NOT want them, I push for the speaker icon being optional. There must be a way to be able to have the icon showing or not showing with the object.
When I open a Smart Notebook version of a file with the same kind of music objects, there are no speaker icons.

I'm afraid that I am unable to upload my files here as I keep getting an error message, however Tech Agent Joel Lawlor does have a music file related to what I was working on.