>> Question: Since the doorway to be bedroom is less than 170 cm wide, does 
>> that mean those waves can't leave the room? Or does the fact that it's 
>> more than 170 cm tall negate that?
> 
>   I think you have a misconception of what wavelength means. The misconception
> probably comes from those 2D drawings of wave functions.
> 
>   A sound wave (nor an electromagnetic wave for that matter) is not some
> kind of sine wave which goes through the air. The sine wave function you
> see drawn on a picture is just the representation of the function which
> tells which direction the wave is "pushing" at certain point (and how
> "strongly" it's "pusing"). The sine wave drawing is just a graph which maps
> time to amplitude ("strength" of the sound wave), it's in no way meant to
> represent the *physical* appearance of a sound wave.
> 
>   A sound wave is simply a phenomenon of air molecules pushing (and pulling)
> adjacent air molecules. The phenomenon traverses through air. The maximum
> strength at which this "pushing" happens is the amplitude of the wave, and
> the rate of change between "pushing" and "pulling" is the frequency. The
> distance between two "pushing" peaks is the wavelength.

...all of which is true. However, a simple experiment with a wavetank 
quickly demonstrates that, for some reason that I don't comprehend, 
large waves won't go through small gaps, and yet small waves will. This 
is the precise opposite of what you would expect, but the results are clear.

(This also explains why animals that use echo-location use such 
high-frequency sounds; they give better spatial resolution. I might even 
go as far as to say that's why electron microscopes give better 
resolution than light microscopes...)

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