Another repost, I'm afraid (from two years ago and sadly still relevant, too). Normal service will resume...
There is an invention, widely used in our modern world and currently available from many a retail emporium. It's not a startling new innovation. It has been in existence for the best part of one hundred years, as it naturally developed alongside the technology it supports. They are available in a wide variety of shapes, be they circumaural or supra-aural, and are driven in various ways – dynamic, electrostatic and so on and so forth. Yes, there are some risks involved in excessive use of this device but there are inherent risks in excessive use of anything (the clue's in the word there – "excessive").
In basic terms, it's a pair of transducers that receive an electrical signal and converts said signal into an audible sound wave. These transducers are placed in close proximity to the aural cavity and provide the recipient with musical or speech-based entertainment.
They're called headphones. And, if you're listening to your fucking shit music on the bus, you should damn well use them instead of inflicting your awful musical taste on the rest of us in an irritating and tinny fashion.