Vibrations, Waves and Sound. Unit 7: Vibrations, Waves & Sound Chapter 20: Sound. 20.1 Properties of Sound 20.2 Sound Waves 20.3 Sound, Perception, and Music. Key Question: What is sound and how do we hear it?. 20.1 Investigation: Sound and Hearing. Objectives:
Vibrations, Waves and Sound
What is sound and how do we hear it?
Each person is saying “Hello”.
The sound would be behind the plane, racing to catch up.
To record a sound you must store the pattern of vibrations in a way that can be replayed and be true to the original sound.
Does sound behave like other waves?
The ultrasound image
above is a heart.
If the long pipe has a frequency of 528 Hz, what is the frequency of the short pipe?
Fourier’s theorem says any complex wave can be made from a sum of single frequency waves.
A complex wave is really a sum of component frequencies.
A complex wave can be made from a sum of single-frequency waves, each with its own frequency, amplitude, and phase.
How can we observe sound as a wave?
How can we use the speed of sound and certain frequencies to build a basic instrument based on wavelength?
A frequency spectrum is a graph showing the different frequencies present in a sound.
Sound containing many frequencies has a wave form that is jagged and complicated.
Which letter represents a soft sound lasting 5 seconds?
What is it’s frequency?
Deafness is poorly understood in general.
For instance, there is a common misconception that deaf people live in a world of silence.
To understand the nature of deafness, first one has to understand the nature of hearing.