Transcript Chapter 2 – The Nature of Sound

Chapter 21 – The Nature of
Sound
Section 4 – Sound Quality
pp. 618 - 621
TERMS TO LEARN
• Sound quality – the result of
several pitches blending together
through interference
WHAT IS SOUND QUALITY?
• If the same note is played with the same
loudness on two different instruments,
could you tell the instruments apart
without looking?
• Yes, you could because the sounds
instruments produce are not the same.
WHAT IS SOUND QUALITY?
• The notes sound different because each
instrument produces several different
pitches: the fundamental and several
overtones.
• The result of several pitches blending
together through interference is called
sound quality.
SOUND QUALITY OF
INSTRUMENTS
• The difference in sound quality of
instruments comes from structural
differences in the instruments
(what the instrument is made of
and how the instrument is made).
3 MAIN FAMILIES OF
INSTRUMENTS
• String instruments
• Wind instruments
• Percussion instruments
STRING INSTRUMENTS
• How they make sounds: They produce sound
•
when their strings vibrate after being plucked or
bowed.
See Figure 2 on p. 619 for comparison of cello
and electric guitar.
WIND INSTRUMENTS
• 2 types of wind instruments:
–Woodwind
–Brass
WOODWINDS
BRASS
WIND INSTRUMENTS
• How wind instruments produce
sound: a vibration is created at
one end of its air column, and
then the vibration creates
standing waves in the air column.
• See Figure 3 on p. 620.
PERCUSSION
PERCUSSION
• How they make sounds: They
produce sound when they are struck
MUSIC OR NOISE?
• Noise is any undesired sound that
includes a random mix of pitches.
• Music is sound that has a pleasing
quality, a definite repeated timing
called rhythm and an identifiable
pitch.
NOISE POLLUTION
• When noise reaches a level that causes
pain or damages the body it is called noise
pollution.
• Noise pollution can damage the inner ear,
causing permanent hearing loss.
• Noise pollution can contribute to
sleeplessness, high blood pressure and
stress.
WHITE NOISE
• This is an equal mixture of all frequencies
(like white light is a mixture of all colors).
• White noise machines are used to calm
people and help make them sleep.