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 N/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 = ? s

(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.