Audiogram of the Northern fur seal in air (Callorhinus ursinus)
Data from:
Babushina, Ye.S., Zaslavskii, G.L., and Yurkevich, L.I. (1991) Air and underwater hearing characteristics of the northern fur seal: Audiograms, frequency and differential thresholds. Biophysics, 36, 909-913.
Schusterman, R.J., and Moore, P.W.B. (1980) Auditory sensitivity of northern fur seals (Callorhinus ursinus and a California sea lion (Zalophus californianus) to airborne sound. Journal of the Acoustical Society of America, 68, Suppl. 1, S6.
Aaverage absolute thresholds in air (in dB re 2 µN/m2) for Northern fur seals (A and B as indicated above)
|
Frequency (in kHz) |
Individual Thresholds (in dB) |
Average |
|
|
Babushina et al. |
Schusterman & Moore |
||
|
.100 |
72 |
|
72 |
|
.200 |
60 |
|
60 |
|
.300 |
53 |
|
53 |
|
.500 |
44 |
|
44 |
|
1 |
29 |
29 |
29 |
|
2 |
20 |
9 |
14.5 |
|
4 |
|
22 |
22 |
|
5 |
11 |
|
11 |
|
8 |
|
13 |
13 |
|
10 |
15 |
|
15 |
|
16 |
17 |
7 |
12 |
|
20 |
37 |
|
37 |
|
25 |
48 |
22? |
? |
|
34 |
|
34? |
? |
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 |
.110 |
— |
|
60 |
.200 |
— |
|
50 |
.360 |
? |
|
40 |
.610 |
? |
|
30 |
.960 |
? |
Additional Parameters:
Body weight = ? g
Functional interaural distance = ? µs
(Time required for sound to travel around the head from one auditory meatus to the other.)
Comments: Threshold values taken from data tables and graphs in Babushina et al., 1991, and Schusterman and Moore, 1980.