"horror vacui" on wikipedia doesn't really seem to be turning up anything appropriate to explain what you're meaning?

“horror vacui” (Latin) - “dread of the void”

I suppose the neighbours are of the sort, like many seemingly, who cannot tolerate silence.

You might know it as "Nature abhors a vacuum". Originally it was a statement of Cartesian physics: the idea was that "action at a distance" was impossible, and since distant objects did clearly interact (through gravity and light), all of space has to be completely filled with particulate matter (assumed to be in vortex motion). From this and "cogito ergo sum" it was possible to build a model of physics which extended to the ethics of how you should treat your dog.

However here it is used as a simple figure of speech rather than literally: the neighbours don't like to lrave anything unfilled with sound.