Audiogram of the ringed seal in water (Pusa hispida)
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Data from: Terhune, J.M., and Ronald, K. (1975) Underwater hearing sensitivity of two ringed seals. Canadian Journal of Zoology,Ìý 53, 227-231.
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Average absolute thresholds (in dB re 20 µN/m2) for two ringed seals under water
|
Ìý Frequency (in kHz) |
Average Threshold (in dB) |
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| Ìý | ||
|
1 |
13.5 |
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|
1.4 |
17.5 |
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|
2 |
18 |
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|
2.8 |
19 |
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|
4 |
13.5 |
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|
5.6 |
13 |
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|
8 |
15.5 |
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|
11.3 |
8.5 |
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|
16 |
8.5 |
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|
22.9 |
10.5 |
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|
32 |
13.5 |
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|
44.9 |
10.5 |
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|
55 |
26 |
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|
64 |
48 |
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|
90 |
53.5 |
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Lowest and highest frequencies audible at sound
pressure levels (SPL) ranging from 30 to 70 dB SPL
|
SPL (in dB) |
Lowest audible frequency (in kHz) |
Highest audible frequency (in kHz) |
|
70 |
— |
— |
|
60 |
— |
(70) |
|
50 |
— |
66 |
|
40 |
— |
60 |
|
30 |
— |
56 |
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Additional Parameters:
Body weight = 90 kg
Functional interaural distance= 80 µs
(Time required for sound to travel around the head from one auditory meatus to the other.)
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Comments: Threshold values taken from Terhune and Ronald,1975; values converted from a reference level of 1 microbar.
For a good discussion of air and water hearing, see Kastak, D., and Schusterman, R.J. (1998) Low-frequency amphibious hearing in pinnipeds: Methods, measurements, noise, and ecology. Journal of the Acoustical Society of America, 103,2216-2228.