What are sound waves made of and why can't we hear some?

[amitmis]

hi,

first - i want to tell you I'm pretty good at english, but it's not my mother tongue, and i still use babylon dictionary sometimes, to read answers, and questions. so - i'll have to ask you to lower the english level (not so rich language...). thank's.

second - my question - what are sound waves made of?
and why are there sounds that we can't hear?

thank's
amit

 

[Tzar]

Sound waves are vibrations of air particles (or any other medium, technically). Your ear can detect these vibrations and your barin then interprets that as data, which we call sound. The reason there are sounds that's we can't hears is because you ear can only detect frequcies of a certain range. Anything outside that rage, and it won't be detected.

 

[bomba923]

Sorry, just want to add the term ; (since no has done so yet)

*Sound waves are longitudinal waves

composed of subsequent compressions and rarefactions of particles in a medium