[hoopladler]

A replacable battery doesn't cost 150$. It's just one screw. The reason why headphones are much cheaper than hearing aids is mainly economies of scale.

I think the main reason why headphones often suck are cultural, not mechanical. If you make stuff in capitalism, it being cheap is always a great selling point, even if it craps out after a couple of weeks of use. So you get the whole market crowded with useless junk, and well-made stuff gets crowded out. Stuff that, from a technological perspective, is outdated, works better than new stuff because of this culture. It doesn't mean that the new technology isn't better. It just means that, with an attitude like ours, we could make crud using any technology.