Audiogram of the tree shrew (Tupaia glis)
Ìý
Data from: Heffner, H.E., Ravizza, R.J., and Masterton, B.(1969) Hearing in primitive mammals, III: Tree shrew. Journal of Auditory Research, 9, 12-18.
Ìý
Absolute thresholds (in dB re 20 µN/m2) for four tree shrews (A and B are individual animals tested using a conditioned suppression procedure, C is the mean of two animals tested using a grill-box avoidance procedure. The mean is equally weighted for the four animals.)
|
Ìý Frequency (in kHz) |
Individual Thresholds (in dB) |
Ìý Average |
||
|
A |
B |
C |
||
|
.125 |
— |
— |
57 |
57 |
|
.250 |
54 |
48 |
49 |
50 |
|
.500 |
24 |
28 |
33 |
29.5 |
|
1 |
26 |
32 |
22 |
27.5 |
|
2 |
21 |
16 |
12 |
15 |
|
4 |
17 |
13 |
4 |
9.5 |
|
8 |
8 |
16 |
-1 |
5.5 |
|
16 |
-13 |
-8 |
0 |
-5 |
|
32 |
4 |
8 |
8 |
7 |
|
60 |
64 |
60 |
— |
62 |
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 |
.110 |
60 |
|
50 |
.250 |
52 |
|
40 |
.350 |
46 |
|
30 |
.500 |
40 |
Additional Parameters:
Body weight = 125 g
Functional interaural distance= 136µ²õ
(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.