Infrasound and UltrasoundbyAlyssa Shoultes

INFRASOUND AND ULTRASOUND IN ORGANISMS.

This section deals with how infrasound/ultrasound is used in organisms.

DolphinsDolphins use a type of ultrasound called

“sonar” to communicate with others.They also use this to make mental “maps” of

murky waters they may be in, since the sonar bounces off of objects in the area and returns back to them.

From left: The workings of sonar from the dolphin’s melon to a fish. The dolphin, one animal capable of using ultrasound.

Blue WhalesThe blue whale uses infrasound.Being more of a solitary creature, they emit

loud and long-traveling infrasound so they can keep in contact with other whales from a distance.

BatsBats are capable of both hearing and

emitting ultrasounds. They emit ultrasounds , hear insects that

emit ultrasounds and figure out where they are. They, in turn, use this to catch or find their next meal.

This process is called echolocation.

From left: a bat. A diagram showing how echolocation works.

Tiger MothsTiger Moths emit ultrasounds.They use it to find a mate and to emit clicks

that “jam” a bat’s echolocation from finding it.

ElephantsElephants are also capable of using

infrasound. They use it to communicate between herds

and to warn about predators in the area.Their lower sound and longer wavelengths

allow the message to travel for several miles

INFRASOUND AND ULTRASOUND IN HUMANS

This section deals with the effects of both waves on humans.

Infrasound EffectsAlthough 20Hz is the lowest sound a human

ear can pick up, certain conditions and a high volume can make infrasound audible.

The addition of infrasound has been reported to cause feelings of fear. Moviemakers picked up on this and used it in several movies, most notably in the 2009 release Paranormal Activity.

Ultrasound EffectsUltrasound is used in the medical field to

monitor a fetus, check for cancers, look into organs for any potential problems, among other things.

DIFFRACTION, REFRACTION, REFLECTION, AND CONSTRUCTIVE/DESTRUCTIVE INTERFERENCE

Here’s some examples of all of those said above and how they impact our daily life.

Constructive/Destructive Interference

Constructive Interference Destructive Interference

Placing two speakers next to each other and playing the same song with them.◦ This is constructive

interference since the two noises join together in unison and make it louder.

Dead spots in a concert hall. ◦ This is destructive

interference since some spots catch noise and it cancels itself out.

◦ This is avoided with proper design.

Diffraction and Refraction

Diffraction Refraction

Hearing others speak when they pass around a corner.◦ This is diffraction since

their voices are forced to bend around a corner to be heard.

Seeing a “broken” spoon in a cup of water.◦ This is refraction since

the light bends when it goes from one medium (air) to another (water) and back to the first.

ReflectionsLooking into a mirror

◦This would be reflection since the light would bounce off of the surface (the mirror) and return back.