Sound & Waves

A primer for Animals & hEaringSound & Waves

Sound is Vibration

Vibrations create Waves

Characteristics of Waves

Amplitude

Characteristics of Waves

Characteristics of Waves

Frequency in a Sound Wave determines Pitch

Describing Waves (rope demonstration)

Frequency

Amplitude

Wavelength

Period = the time between the wave crests

Describing Sound

Frequency = Pitch

Amplitude = Volume (how loud it sounds)

What is the term for reflected sound?

Tuning Forks & FrequencyWhich tuning fork will have a higher pitch?

UNITSFrequency is measured in Hertz

Hertz = Cycles per Second, ie. the number of S curves in one second.

These Tuning forks create sounds with frequency 256 Hz & 512 Hz.

Tuning Forks & FrequencyWhich tuning fork will have a higher pitch?

UNITSFrequency is measured in Hertz

Hertz = Cycles per Second, ie. the number of S curves in one second.

These Tuning forks create sounds with frequency 256 Hz & 512 Hz.256 Hz512 Hz

Not all Frequencies of Vibration can be Heard

Day 2 Materials4 StethocopesTuning forksEar funnel setupFlour baggie/watch/air baggieSlinkyFunnel/milk jug to hold up to the ear

Describe this wave in terms of frequency, amplitude and wavelength.

Day 2: Movement of SoundSound Waves Travel through:GasesLiquidsSolids

Sound does NOT travel through a vacuum.

It requires a medium. Air is the medium for this sound wave

Compression Wavehttp://www.acs.psu.edu/drussell/Demos/rad2/mdq.html

http://en.wikipedia.org/wiki/File:Onde_compression_impulsion_1d_30_petit.gifA Slinky Can be a Hands On model of movement of a Compression Wave

If sound is a compression wave,which medium do you think it will move faster through?

Sound travels more efficiently through solids than gases. The sound of the ticking watch will be louder through the flour than through the air.

Which will be louder?

Sound travels more efficiently through liquids than gases

Speed of SoundSubstancemeters/secmiles/hoursvacuum00Carbon dioxide270604Air340760Hydrogen1,3202.950Water1,4703,290Glass5,00011,180Iron5,12011,450Direction of SoundThe brain interprets direction from which a sound orginates by the difference in time it takes to get to each ear.Amplify SoundIf sound is created by vibrations, what is a strategy for making a sound louder?