Transcript Sound Waves - Haiku for Ignatius

Sound
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How are sounds Classified?
How are sounds produced?
How are sounds different?
How are sounds measured?
How fast does sound move?
Sound Waves
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Each Sound wave has unique pattern
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Frequency
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Wavelength
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Amplitude
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
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
Amplitude of Sound
• Volume control
• Loudness
• Strength of the wave ( measured in db “decibels”)
• Energy of the wave
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).
Speed of Sound
• Velocity(v) of a wave= Frequency (f) times the wavelength (l)
• V=fl
• The speed of propagation of sound in dry air at a temperature of 0°C
(32° F) is 331.6 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)
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
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.
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
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
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.