acoustics video of the day

Breaking the Silence: The Speed of Sound

Light travels much faster than sound. Learn more about the speed of sound in this video.


Related Ad Categories

Related Videos
You need the Flash Player version 8.0.0.0 or higher and a JavaScript enabled browser to view this site

browse videos in acoustics

Sort by:

Exploring Sound: Sound Waves

Exploring Sound: Sound Waves (2:03)

The vibrations of an object compacts air molecules in some places (compression) and causes expansion of air in other places (rarefaction).

Exploring Sound: Frequency

Exploring Sound: Frequency (1:28)

Frequency is the rate of vibration of sound and is measured in hertz. One vibration per second is one hertz.

Exploring Sound: Echo Location

Exploring Sound: Echo Location (2:21)

Bats hunt by echolocation. The best condition for an echo is a hard surface. Some materials absorb sound. Curved surfaces are used to reflect sound over a large area.

Exploring Sound: Loudness

Exploring Sound: Loudness (0:28)

Loudness is measured in decibels (as shown in a table). Loud sound can cause hearing loss. People working around loud sounds usually wear protective ear gear.

Exploring Sound: Parts of the Ear

Exploring Sound: Parts of the Ear (0:49)

The parts of the ear and their function are shown in a model and are described.

recently added

Breaking the Silence: Recap of the Sound Videos

Breaking the Silence: Recap of the Sound Videos (1:49)

This clip is a review of the videos on sound and vibrations.

Breaking the Silence: Defining Echo Echo Echoes

Breaking the Silence: Defining Echo Echo Echoes (1:59)

When you yell toward a hard, flat surface, the sound waves bounce back to your ears and you hear your voice as an echo. Hard, flat surfaces reflect sound waves best to create echoes, while soft surfaces absorb sound and don’t create echoes.

Breaking the Silence: How Sound Travels

Breaking the Silence: How Sound Travels (1:38)

Sound travels better through solid objects, like wood or metal, than through air. Water conducts sound better than air, so sounds are louder underwater. In space, there are no air molecules to conduct sound waves-- so there is no sound.

Breaking the Silence: The Speed of Sound

Breaking the Silence: The Speed of Sound (0:48)

Light travels much faster than sound. Learn more about the speed of sound in this video.

Breaking the Silence: How Sound Reaches Our Ears

Breaking the Silence: How Sound Reaches Our Ears (3:29)

A vibrating object causes the air molecules near it to vibrate, creating a sound wave. Sound waves enter the ear, strike the eardrum and make it vibrate, causing small bones in the ear to tremble. Nerves sense these vibrations and signal the brain.

Breaking the Silence: Controlling Pitch When We Talk

Breaking the Silence: Controlling Pitch When We Talk (1:32)

The vocal cords in our throats are two folds of tissue that vibrate as we force air through our windpipes. The more tension in our vocal cords, the higher the pitch of the sound created.

Breaking the Silence: Air and Sound

Breaking the Silence: Air and Sound (1:30)

Air can be made to vibrate. When you blow into a wind instrument, such as a recorder, you make a column of air inside it that vibrates. The pitch of the notes changes as you change the length of the air column.

Breaking the Silence: Pitch and Music

Breaking the Silence: Pitch and Music (2:22)

Musical instruments are designed to produce sounds of many different pitches. A short or thin guitar string will produce sound with a high pitch.

Breaking the Silence: Defining Pitch

Breaking the Silence: Defining Pitch (2:05)

The frequency of a sound determines whether it is high or low. The high or low quality of a sound is called pitch.

Breaking the Silence: Energy and Sound

Breaking the Silence: Energy and Sound (3:33)

The greater the energy input, the larger the vibration and the louder the sound produced. The number of times an object moves back and forth in one second is called frequency, which is measured in hertz (Hz).