Question

Two sound waves of equal amplitude interfere so that the compression of one wave falls on the rarefaction of the other.Which statement is true?
A.No sound is heard.
B.The loudness of the sound increases.
C.There is no change in the sound.
D.The pitch of the sound increased.

Answer 1

are the 2 sound waves travelling in opposite direction ?

Answer 2

The question doesnt say

Answer 3

ok

Answer 4

U know the answer?

Answer 5

i m searching and thinking !

Answer 6

Ok

Answer 7

i think it's D

Answer 8

Sure?

Answer 9

cause i think since the amplitude matches

Answer 10

it may have the effect of the resonance

Answer 11

Ok D it is

Answer 12

is it ?

Answer 13

It wasnt D

Answer 14

What happens to sound waves after they are received by our ears?

Answer 15

well if it is like i said then i guess eardrum would brust :p

Answer 16

do u know answer ?

Answer 17

Nope

Answer 18

@kritima , first of all no frequency/pitch increase won't cause your eardrum to burst! lol no! High frequencies just out out of the range for human hearing (i.e.: dog whistle). What will rupture the eardrum is forceful pressure wave, such as that from an explosion; or a continuous wave that has VERY high decibels (another, logarithmic measure of amplitude)

Answer 19

"Two sound waves of equal amplitude interfere so that the compression of one wave falls on the rarefaction of the other."

+ = compression
- = rarefraction


This is known as destructive interference, and it's how the active noise canceling on Bose headphones that have it work! In the case of those headphones it takes the surrounding sound picked out outside the ear cup with a microphone and digitally adds that "noise with a 90\(^o\) phase shift delay to the audio signal coming into your speakers. The result is your background noise is very effectively removed (unless it's so extreme your speakers can't replicate it).

@QyronB & @kritima , does this make sense now? If you don't believe me spend ~$300 to go buy those headphones and see for yourself! :-)

http://www.bose.com/controller?url=/shop_online/headphones/noise_cancelling_headphones/index.jsp&perfsourceid=K9677&src=K9677&perfsourceid=K9677&src=K9677