Noise in Flight - Is it artificial?
 

I know this sounds like an urban myth, but is it true that 'noise' is pumped into an aircraft to drown out the sounds of the engines?

In some cases, yes. Some of the Dash-8 turboprop aircraft have a noise canceling system in the cabin. It works the same way as noise cancelling headsets. :)

US Airways, in their infinite wisdom, has turned off the system on their Dash-8's (citing cost cuts, as usual), making them louder than the same type of plane operated by Horizon.

As JS said, some Dash 8s have this. Remember though that it is not done to "drown out" the engine noise, but to actively reduce it by generating an out-of-phase signal.

Noise-cancelling technology is kind of counter-intuitive unless you study the physics behind it.

Fortunately we can reap the benefits of the technology without understanding it. ;)

I don't know, but if it is, I don't think it's working very well.