Title:	Location	K-4	5-8	9-12	Description	Discipline
Sound Perception Facts	Kitchen	-	X	X	Auditory perception factoids.

No two people hear exactly alike! Everyone has a uniquely shaped outer ears called pinnae. They color arriving sounds by producing millisecond (thousandths of a second) delays that our brain combines with the original sound. This produces a personalized coloration of any sound we hear.

When listening to stereo speakers, with equal outputs, our ear\brain creates a phantom image in the center! By changing the loudness of each channel, recording engineers can place a sound event anywhere within the space between the speakers.

The speed of sound in air at sea level:

@1.1 ft.\thousandth of a second (or millisecond),

@1,100 feet per second,

@765 miles per hour.

In normal conversation, the air pressure in front of your mouth needs to change by only one millionth the standard air pressure for someone to hear you.

Your ears can detect a cricket chirping a half a mile away.

Though you can't see around corners, you can hear around them! All because sound waves diffract or bend around them.

A sound that vibrates 13,000 times per second has a wavelength of 1 inch.

A sound that vibrates 30 times per second has a wavelength of 36 feet.

Research has shown that unborn infants can detect their mother's voice inside the womb. Do you remember hearing your mother's voice then?

Humans can't hear sounds that vibrate slower than 15 times per second or faster than 20,000 times a second.

The sounds of a honey bee are actually its wings flapping at a rate of 440 vibrations per second.

A blue whale can be detected more than 500 miles away, and a humpback whale is thought to be able to hear others close to 1000 miles away!

Sound travels five times faster in water than in air.

Though moths can detect sound, their cousin the butterfly cannot.