Welcome Back Minions!

Question…

• What do you notice about sound waves?

Similarities

• Did you know there are similarities between electromagnetic waves and sound waves?– Reflection– Diffraction

Reflection

• Sound hitting a surface and bouncing back (or reflecting)

• A reflected sound wave is known as an echo!

Diffraction

• Sound waves can bend around corners!

Properties…

• Properties of sound waves…– Pitch– Loudness• Sound level

Pitch

• Pitch– Description of how high or low the sound seems to a person.– This depends on the frequency of the sound wave.

Pitch

• Normal range of hearing– 20 Hz to 20,000 Hz• Sounds below this range is called Infrasound.• Sounds above this range is called Ultrasound.

Pitch

• Some other ranges…

PITCHHigher Frequency=Higher pitch

Lower frequency= Lower pitch

Loudness

• Loudness– Perception of the

energy of sound– 2 Factors• Amount of energy to

make the sound• Distance from the

source of the sound

Loudness

• Energy– Greater the energy,

the louder the sound!

Loudness• Distance

– Intensity• Closer to source = more intense• As you move from source = less intense

LOUDNESS

Greater Amplitude = Louder soundSmaller amplitude = softer sound

Sound Level

• Measuring loudness– Decibel• How different level of

sounds are measured and compared

Sound Level

• Here is a list of ranges…

SOUND LEVELA measurement of sound pressures (measured in

Decibels (dB))