When does music in public places become noise pollution? You may like at least some kind of music. But the problem is that, in lots of places, you're made to hear somebody else's choice in music. Say you've just landed at an airport. At the airport, the "background"  music may be played loudly. When you are on the way to your hotel, there may be another kind of music played by the taxi driver. Then you finally reach your hotel. But when you are taking the elevator ,there is elevator music. You go out to dinner and end up in a place where the owner of the restaurant thinks music will help make you eat more and spend more. Then a person playing the violin comes around. This is called the "music wallpaper". It is to make you buy more and eat a lot.  Even the government thinks this is "noise pollution," especially when the music is too loud. Noise pollution may be bad for our hearing. It's also bad for some of our daily activities, such as sleeping, conversations and so on. The fact that you can't see, taste or smell it may help explain why it has not received as much attention as other kinds of pollution, such as air pollution or water pollution. The air around us is always filled with sounds, but most of us would not think we are surrounded  by noise. This can be bad for our health. So many people like soft and quiet music in their house. Music in public places becomes noise pollution because   _  .
it's played at the airport it's played by the taxi driver it's played when you are taking the elevator you are made to hear someone else's choice in music