This document covers the Parameters of Sound.

1. Parameters of
Sound
By Prof. Hitesh Dholakiya
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Engineering Funda Android App Audio Video YT Playlist

2. Outlines
 Intensity
 Phon
 Sone
 Pitch
 Timbre
 Overtones and Harmonics
 Interval and Octaves
 Example on Interval and Octaves
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Engineering Funda Android App Audio Video YT Playlist

3. Intensity
 It there in terms of 𝑊/𝑚2
 Threshold of hearing
 It is just about audible sound
 it has intensity of 1 pico-watt/𝑚2
 It has pressure of 2 × 10−5𝑁/𝑚2
 Threshold of pain
 It has maximum painful sound, beyond that eardrum will get fail
 it has intensity of 10 watt/𝑚2
 It has pressure of 63 𝑁/𝑚2
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Engineering Funda Android App Audio Video YT Playlist

4. Intensity
of
Sound
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5. Phon
 The loudness of intensity of sound in dB over threshold of hearing as
perceived by the ear at 1000 Hz is called ‘Phon’.
 Intensity at 1000 Hz is 0 dB – zero phon loudness
 If it is 40 dB – loudness is 40 phon
 If intensity of 60 dB at 40 Hz gives the same loudness as 0 dB
intensity at 1000 Hz – loudness at 40 Hz is – zero phon – not 60 phon
 So – loudness in phons at 1000 Hz – intensity of sound in dB
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6. Sone
 It is used to determine the increase in loudness.
 Loudness sensation produced by 1000 Hz sound of 40 dB (i.e. 40
phon) is called 1 sone.
 Increase in sone value in dB is given by (P-40)*log2, where P is the
loudness in phons.
 Relationship between sones (L) and phons (P) is given by
𝟏𝟎 𝐥𝐨𝐠 𝑳 = 𝑷 − 𝟒𝟎 𝐥𝐨𝐠 𝟐
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7. Pitch
 Pitch is determined by frequency of sound.
 Frequency is measured in terms of Hz.
 Human ears can perceive a range of frequencies from 20Hz to 20kHz.
 But in speech and music, pitch of sound depends not only on
frequency but on intensity as well. The unit of pitch is ‘MEL’.
 One MEL is a tone of 1000Hz and 40dB intensity.
 The relationship between pitch and frequency is non linear.
 So human needs higher intensity to listen low frequencies and lower
intensity to listen higher frequencies.
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8. Timbre
 Timbre means tonal characteristics.
 We distinguish between sound different sounds according their timbre.
 Our voices also have different timber.
 Timbre is defined as per sets of different frequency proportion.
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9. Overtones and Harmonics
 Sound consists group of frequencies.
 Frequencies other than the fundamental frequency are called
‘Overtones’.
 All the frequencies are considered in Harmonics.
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10. Interval and Octave
 Ratio of two frequency is referred as interval
 e.g. If frequency range is given by 100Hz to 800Hz then interval will be
𝑓1: 𝑓2 = 1: 8
 Octave is defined as
𝑂𝑐𝑡𝑎𝑣𝑒𝑠 =
log
𝑓2
𝑓1
log 2
 e.g. If frequency range is given by 100Hz to 800Hz then octaves will be 3.
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11. Example on Interval and Octave
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