1. Sound How are sounds Classified? How are sounds produced?
How are sounds different?
How are sounds measured?
How fast does sound move?

2. Sound Waves Each Sound wave has unique pattern Frequency Wavelength
Amplitude

3. Sound mediums
A medium is a material that sound, a form of energy, need to transfer
Speed of sound
Solid : Fast speed
Liquid : Medium speed
Gas : Slow Speed
Standard Temperature and Pressure = 3.31 x 102 m/s
Vacuum : No Sound

4. Frequency of Sound Pitch of the sound
Musical notes: there are 12 notes on a staff from A to G#
Bass : Low frequency 0 to 300 Hz
Mid range : “voice” 300 to 6,000 Hz
Treble : High frequency, Above “middle” C note, 6,000 to 20,000 Hz
Spectrum of frequency

5. Amplitude of Sound Volume control Loudness
Strength of the wave ( measured in db “decibels”)
Energy of the wave

6. Reflection and Refractions of Sound waves
Echo
Reflection of sound off a surface (Acoustics (Greek akouein,”to hear”),. It is more commonly used for the special branch of that PHYSICS that deals with the construction of enclosed areas so as to enhance the hearing of speech or music.
Reverb (Electronic echo)
Resonance
electronic envelope Helmholtz Resonator, spherical vessel of metal or glass with an opening and an earpiece on opposite sides.
The ear canal acts enhancing frequencies in the range from 1000 to 4000 Hz (hertz, or cycles per second).

7. Speed of Sound
Velocity(v) of a wave= Frequency (f) times the wavelength (l)
V = f l
The speed of propagation of sound in dry air at a temperature of 0° C (32° F) is m/sec (1088 ft/sec). If the temperature is increased, the speed of sound increases; thus, at 20° C (68° F), the velocity of sound is 344 m/sec (1129 ft/sec)

8. Resonance of Sound
Any oscillating object has a natural frequency, which is the frequency an oscillating object tends to settle into if it is not disturbed.
The phenomenon in which a relatively small, repeatedly applied force causes the amplitude of an oscillating system to become very large is called resonance

9. Interference of Sound Constructive interference
The displacement of the disturbance of 2 waves are the same (Similar sounds
Frequency are the same or multiple.
Destructive interference
The displacement of the disturbance of 2 waves are the different (Unlike sounds)
Frequency are the different or not a direct multiple.

10. Beats
The pulse, or pattern of regular accents, of a musical piece can be broken into individual pulses, or beats
a fractional symbol in which the numerator specifies the number of beats per bar, and the denominator specifies the relative note value assigned to one beat

11. Doppler Effect
The frequency of the perceived wave is changed by the motion of the source
Increasing Frequency when the source approaches the sensor
Decreasing Frequency when the source increases the distance from the sensor

12. Summary
Sounds are created by Moving molecule in the medium ( Solid, Liquid and Gases)
Sounds are measured by Frequency, Wavelength, Speed, and Amplitude.
Sounds can combine by interference
Sounds can be changed by the Acoustics of the Area or the speed of the source
(Doppler Effect)
Sounds are used in many devices.