Question

Some animals communicate by emitting low frequency sound waves. When the animal emits a low frequency sound wave what is the resulting pitch?

Answer 1

Echolocation, also called bio sonar, is the biological sonar used by several kinds of animals. Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for navigation and for foraging (or hunting) in various environments. Some blind humans have learned to find their way using clicks produced by a device or by mouth.
Echolocating animals include some mammals and a few birds; most notably microchiropteran bats and odontocetes (toothed whales and dolphins), but also in simpler form in other groups such as shrews, one genus of megachiropteran bats (Rousettus) and two cave dwelling bird groups, the so-called cave swiftlets in the genus Aerodramus (formerly Collocalia) and the unrelated Oilbird Steatornis caripensis.

for more info refer wikkipedia

Answer 2

08surya's information came straight from Wikipedia (first two paragraphs).
http://en.wikipedia.org/wiki/Animal_echolocation
(Just citing that for him)

I think the goal of this question is just, low frequency is what kind of pitch?

Well! Low frequency means that the compressions and rarefractions of the air are less frequent. More time in between each maximum compression and maximum refraction.

How it works with our ears:
The compression and rarefraction of the air is air pressure differences. The air pressure on the outside of our eardrums is changing, while the inside doesn't so much. So the air pressure moves the ear drums back and forth, which we register through nice biological things. The number of back and forth movement per time is the frequency, and it is that of the air's sound wave frequency.

So, long story short, our ears detect the sound wave frequency from the air.

And then the brain translates: low frequency is low pitch. High frequency is high pitch.

You might notice that the low frequency = low pitch sounds good. (Pun intended.) Low frequency carries better - interference will not change the sound wave as noticeably. So, low pitches carry better. And the opposite can be said of high frequency = high pitch - it carries less well.


I hope this has helped! Let me know if you have any questions!

Answer 3

@theEric

why can't we hear above 20k and below 20?

i always thought if its below 20.. the frequency is too low to even oscillate our ear drums.. (or it won't be a nice oscillation that our brain can detect).. and if the frequency is tooo high then again our ear drums will refuse to oscillate
but somehwere i read.. our ear drums do oscillate.. its just that we don't register.. anythoughts?!

Answer 4

@Mashy I'm not sure! I might do research later, though! :)

Maybe, for high frequency, the eardrum material is too stiff to register high sounds as well. And maybe, for low frequency, our brain either can't read or doesn't care for low oscillations. That might be true for high frequency, too! That's all just speculation, based on my limited knowledge of physics.

The biology of the human ear might show if there's a physical limitation to what we can hear. But I don't know that stuff! I know some things about the ear, but not all of its processes. I'm probably a bit off in thinking that the eardrum vibrations move three tiny bones in the ear that vibrate a fluid filled and cilia filled sac where the cilia vibrate according to the eardrum's vibrations. I did learn, once, how the cilia's movement caused some cellular response or something. I'm far from understanding this though!

So, I don't know! But I might look it up later! All I know is that, for a number of mammals at least, the hearing range encompasses the speaking range.

Answer 5

@Mashy !

http://www.youtube.com/watch?v=UCs6M0mKlNM

There is an overview of the hearing process. So, despite the stiffness of the eardrum, the limit might just be imposed by the structure of the cochlea! I haven't done any real research though.. I have homework and stuff.. :) Enjoy!

Answer 6

looked nice :)