Sound Reflections (05:56)

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An acoustic engineer explains how listening to sounds can help people understand their environment, especially in the absence of light. Sound reverberates differently off different materials.

Sound Waves (04:24)

Sound travels in waves and slightly changes every time it hits a surface. The sound reflection provides information about what changed the wave. People can hear objects they cannot see because of diffraction.

Sound Localization (05:40)

Localization is the ability to determine where a sound in coming from; see a demonstration. Humans and animals use localization subconsciously. The shape of the ear also helps locate a noise.

Sound Detector (07:23)

The ear is a series of complex factors that allow for sound detection. Damage to a part of the series leads to hearing problems. Hearing aids and cochlea implants replace missing or damaged parts of the ear.

Sound Resonance (03:57)

The cochlea lets humans know the frequency of a sound through resonance. The basilar membrane has different natural frequencies; the part that matches the frequency coming in will vibrate the most.

Evolution (05:16)

The cochlea and hearing developed when all life was still underwater. Fish developed fluid filled cavities, which allowed them to detect sound. The system had to adapt when life moved to land.

Underwater Acoustics (07:38)

Sound can be used to find items hidden from light and can travel great distances underwater. Oceanographers use sonar to study the ocean floor.

Sound of Saturn's Moon (05:00)

The Huygens spacecraft recorded sounds as it passed through Titan's atmosphere. Sonar was used to map the surface.

Credits: Using Sound (00:42)

Credits: Using Sound