Page 376 - Color_Atlas_of_Physiology_5th_Ed._-_A._Despopoulos_2003

A. Wavelength, wave amplitude and wave types
1 2 Pure tone

Wavelength
λ Ampli- λ
Sound pressure – 0 tude (a) Fundamental and overtones Sound Physics and Thresholds
+

Change in frequency
Wavelength Higher pitch λ
+ λ Noise

0
–
Lower pitch
? λ ? Plate 12.27
Change in intensity
Quieter Louder 3 Beat tone
+
Ampli-
tude
0
–

B. Sound pressure, sound pressure level and loudness level
2 . 10 2 140
Phon Pain threshold
130 phon
130
2 . 10 1 120
Pneumatic drill
120 phon
2 100 100
70–90 phon
2 . 10 –1 80 80 Heavy traffic
Principal
2 . 10 –2 60 conversational 60 Loudness level (phon) Normal
conversation
range
50–70 phon
Sound pressure (Pa) 2 . 10 –3 Sound pressure level (dB SPL) 40 40 Whisper
20–40 phon
–4
2 . 10
20
20
Absolute
threshold
4
–5
2 . 10
0
20 31.5 63 250 1000 4000 16000 4 phon
Frequency (Hz)
363
Phon = dB at 1000Hz
Despopoulos, Color Atlas of Physiology © 2003 Thieme
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