Musical Sounds Physical Science 101 Chapter twenty Amanda

Exercise What is decibel level of a sound that is 1000 times louder than

What Exercise is decibel level of a sound that is 10, 000 times

it’s actually easy intensity 10 (101) louder 10 d. B higher intensity 100 (102)

What Exercise is decibel level of a sound that is 1000 times louder

Quality The quality of sound from a musical instrument depends on the number of

Fourier Any periodic signal can be made up from a sum of harmonic waves

Fourier (1, 0, -(1/9)) Any periodic signal can be made up from a sum

Fourier (1, 0, -(1/9), 0, +(1/25)) Any periodic signal can be made up from

Fourier (1, 0, -(1/9), 0, 1/25, 0, -(1/49), 0)

Fourier (1, 0) Any periodic signal can be made up from a sum of

Fourier (1, 0, (1/3)) Any periodic signal can be made up from a sum

Fourier (1, 0, 1/3, 0, 1/5) Any periodic signal can be made up from

Fourier (1, 0, 1/3, 0, 1/5, 0, 1/7) Any periodic signal can be made

Compact Discs binary numbers 00 01 10 11 100 101 10000 1111 0 1

Compact Discs Sample rate of 44, 100 bytes per second This gives 0 to

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Musical Sounds Physical Science 101 Chapter twenty Amanda Hyer

Noise

Music

Pitch High Low

Intensity Loudness Soft Loud

Sound Intensity

Decibel Sound Level

Exercise What is decibel level of a sound that is 1000 times louder than the threshold of human hearing? Given: Intensity/10 -12=1000=103 Wanted: decibel level Solution: d. B=10 log(Intensity/10 -12) d. B=10 log(103) = 30 d. B

What Exercise is decibel level of a sound that is 10, 000 times louder than a sound of 50 d. B? Given: 50 d. B=d. B 1 and Int 2 =10, 000 Int 1 Wanted: d. B 2 Solution: Int 1=100, 000 (10 -12) Int 2=10, 000*100, 000 (10 -12)= 109(10 -12) d. B 2=10 log(109) = 90 d. B

it’s actually easy intensity 10 (101) louder 10 d. B higher intensity 100 (102) louder 20 d. B higher intensity 1000 (103) louder 30 d. B higher intensity 10, 000 (104) louder 40 d. B higher intensity 1, 000 (106) louder 60 d. B higher

What Exercise is decibel level of a sound that is 1000 times louder than a sound of 70 d. B? Given: 70 d. B=d. B 1 and Int 2 =1000 Int 1 Wanted: d. B 2 Solution: d. B 2 is 30 d. B higher d. B 2=70+30 d. B=100 d. B

Quality The quality of sound from a musical instrument depends on the number of higher harmonics included with the fundamental frequency.

Quality (a pure tone)

Quality (1, . 4, 0, . 2)

Quality (1, 0, 0, . 3, 0, 0, . 5)

Fourier Any periodic signal can be made up from a sum of harmonic waves (sine waves).

Fourier (1, 0, -(1/9)) Any periodic signal can be made up from a sum of harmonic waves (sine waves).

Fourier (1, 0, -(1/9), 0, +(1/25)) Any periodic signal can be made up from a sum of harmonic waves (sine waves).

Fourier (1, 0, -(1/9), 0, 1/25, 0, -(1/49), 0)

Fourier (1, 0) Any periodic signal can be made up from a sum of harmonic waves (sine waves).

Fourier (1, 0, (1/3)) Any periodic signal can be made up from a sum of harmonic waves (sine waves).

Fourier (1, 0, 1/3, 0, 1/5) Any periodic signal can be made up from a sum of harmonic waves (sine waves).

Fourier (1, 0, 1/3, 0, 1/5, 0, 1/7) Any periodic signal can be made up from a sum of harmonic waves (sine waves).

Compact Discs binary numbers 00 01 10 11 100 101 10000 1111 0 1 2 3 4=22 5 16=24 255

Compact Discs Sample rate of 44, 100 bytes per second This gives 0 to 10, 000 Hz frequencies