In the book "Inventions of Daedalus" there are hundreds of such ideas.
But it came out a long time ago, and some ideas - perhaps - have already been implemented.
Other books with a selection of unrealized inventions to me unknown.
Yeah, there is one. Many people have a nasty voice, especially the bosses. If only there was such a device on your ears, so that you could filter the frequencies according to the user setting, and you would hear, for example, a melodic relaxing tone when an employee from the side tears the air with a magpie wheeze.
The very idea of a product or invention is not patented, as I was told in one law firm. You can only patent a finished product with drawings and technical descriptions