Chapter 2: Sound Review PowerPoint

Describe resonance. How can it be useful? Resonance occurs when an object is made to vibrate at its natural frequency by absorbing energy from another object vibrating at the same frequency. It can be used to amplify the sound.

How do sounds transfer from you to a friend when speaking? Air molecules collide with one another transferring energy

In what medium does sound travel the fastest? It travels fastest in solids.

What is sound diffraction? When sounds bends around a barrier (around a corner of a building or around a door).

What do your vocal cords do that help you produce speech? The vocal cords vibrate which produces speech.

What is reverberation? It is when sounds is reflected.

What is music? Music is a combination of sounds. It has distinct pitches and a specific pattern.

What is loudness? Loudness is the human perception of the energy that a wave carries.

Describe the Doppler Effect. How does the pitch (appear) to change? The Doppler Effect is when there is change in the pitch of a sound. It happens when the sound source and the listener are moving relative to one another. When the sound source moves toward the listener the pitch sounds higher. When the sound source moves away from the listener the pitch sounds lower.

What is noise? Noise is made of sounds that are disorganized and have an irregular pattern.

What does natural frequency depend on? Natural frequency depends on the size, shape, and material that makes up the object.

What is pitch? How do we measure pitch? Pitch is how high or low a sounds is. Pitch is measure in Hertz.

What is the job of the outer, middle, and inner ear? The outer ear’s job is to gather sound. The middle ear’s job is to amplify sound. The inner ear’s job is to interpret sound.

What is an echo? An echo is a reflected sound wave.

When amplitude increases, what happens to loudness, energy, pitch, frequency, and wavelength? Loudness and Energy increase. Pitch, Frequency, and Wavelength stay the same.

When frequency increases, what happens to loudness, speed, pitch, amplitude, and wavelength? Pitch increases. Wavelength decreases. Loudness, speed, and amplitude stay the same.

What causes hearing loss? Disease Age Exposure to loud sounds

Describe the compressions and rarefactions of sound waves. Compressions form when the vibrating object pushes the air molecules together. When the vibrating object moves back, it creates an area with fewer molecules to form a rarefaction.

Describe how hearing-impaired people can dance. They can feel the vibration of the music through the floor.

Why can’t sound travel on the moon? The moon has no atmosphere and therefore sound cannot travel.

Contrast natural and fundamental frequency. Natural frequency is the frequency of an object when it vibrates. Fundamental frequency is the lowest frequency that an object can produce.