Audiogram of the ringed seal in water (Pusa hispida)

 

Data from: Terhune, J.M., and Ronald, K. (1975) Underwater hearing sensitivity of two ringed seals. Canadian Journal of Zoology,  53, 227-231.

 

Average absolute thresholds (in dB re 20 ľN/m2) for two ringed seals under water

 

 

Frequency

(in kHz)

Average Threshold

(in dB)

1

13.5

 

1.4

17.5

 

2

18

 

2.8

19

 

4

13.5

 

5.6

13

 

8

15.5

 

11.3

8.5

 

16

8.5

 

22.9

10.5

 

32

13.5

 

44.9

10.5

 

55

26

 

64

48

 

90

53.5

 

 

 

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

 

 

Additional Parameters:

Body weight = 90 kg

Functional interaural distance= 80 ľs

(Time required for sound to travel around the head from one auditory meatus to the other.)

 

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.