[ryan_j_naughton]

What about when it is a small group playing very low music such that it is quickly drowned out by the sound of the waves and the birds after 10 feet of distance. Headphones are actually impede their enjoyment of the situation there because (a) they cannot easily talk to one another with headphones in (b) they cannot enjoy the mixing sounds of nature and music. In many cases, folk music or classical music at low volume mixed with nature can be very enjoyable for people.

The problem here is you see no value to their enjoyment of these things and thus weight their enjoyment of such experience at zero while their interruption of your situation as an invasion. But if you force them to stop listening to music, you too are disrupting or invading their lives. That's the two-sided nature of any negative externality and attempts to internalize it. We all need to view this from the perspective of social costs and social benefits (i.e. a utilitarian perspective across all people's happiness). The result is almost always a compromise between the two extremes.

[acheron]

Correct. I also see no value to someone’s enjoyment of punching others in the face. I am perfectly fine disrupting and invading their lives to force them to stop punching others in the face.