Audiogram of the big brown bat (Eptesicus fuscus)
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Data from: Koay, G., Heffner, H.E., and Heffner, R.S. (1997)Audiogram of the big brown bat (Eptesicus fuscus). Hearing Research,105, 202-210.
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Absolute thresholds (in dB re 20 µN/m2) for three big brown bats (designated A through C)
|
Ìý Frequency (in kHz) |
Individual Thresholds (in dB) |
Ìý Average |
||
|
A |
B |
C |
||
|
.5 |
>110 |
>110 |
>110 |
No response |
|
.85 |
105.5 |
108 |
105.5 |
106.3 |
|
1 |
101.5 |
98 |
95 |
98.2 |
|
2 |
78.5 |
76 |
79 |
77.8 |
|
4 |
59 |
55 |
58.5 |
57.5 |
|
8 |
26 |
27.5 |
28.5 |
27.3 |
|
16 |
17.5 |
19 |
24.5 |
20.3 |
|
20 |
6.5 |
6.5 |
14 |
9 |
|
32 |
7.5 |
11.5 |
14.5 |
11.2 |
|
45 |
32 |
31.5 |
34 |
32.5 |
|
60 |
— |
14.5 |
19 |
16.8 |
|
64 |
15 |
14.5 |
17 |
15.5 |
|
90 |
37 |
31.5 |
39 |
35.8 |
|
100 |
54.5 |
— |
— |
54.5 |
|
110 |
69.5 |
— |
— |
69.5 |
|
120 |
81 |
82 |
86.5 |
83.2 |
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 |
2.6 |
110 |
|
60 |
3.7 |
104 |
|
50 |
4.8 |
98 |
|
40 |
6.0 |
92 |
|
30 |
7.5 |
81 |
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Additional Parameters:
Body weight =17 g
Functional interaural distance= 50 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 original data. For an additional audiogram, see Dalland, J.I. (1965) Hearing sensitivity in bats. Science, 150,1185-1186.)