As the sound wave moves away from the source, the wave spreads out and the intensity ____.

• Increases

• Stays constant

• Decreases

• Fluctuates

Loudness of a sound can be measured by a unit called a ____.

• Decibel
• Gram
• Meter
• Volt

The greater the decibel of a sound, the ____ will be the loudness.

• weaker
• quieter
• Greater

• softer

Pin dropping to the floor has a loudness of ____ dB.

• 20 dB

• 10 dB

• 0 dB

• 30 dB

Sound louder than ____ can cause damage to the ears.

• 100dB

• 120dB

• 95dB

• 85dB

Loudness depends on the ____ of a wave.

• frequency
• wavelength
• velocity
• amplitude

Pitch depends on the ____ of a wave.

• amplitude
• frequency
• wavelength
• Decibel

Frequency depends on how ____ the source of sound is vibrating.

• slow
• loudly
• fast
• bright

Sound with high frequency will have ____ pitch.

• low
• high
• fast
• medium

A change in frequency or pitch in relation to the observer is called ____.

• Doppler effect
• Pitch change
• Frequency shift
• Redshift effect