Audiogram of the harp seal in air (Pagophilus groenlandicus)

 

Data from: Terhune, J.M., and Ronald, K. (1971) The harp seal Pagophilus groenlandicus (Erxleben 1777). The air audiogram. Journal of Canadian Zoology, 49, 385-390.

 

Absolute thresholds (in dB re 2 ľN/m2) for a harp seal in air

 

 

Frequency

(in kHz)

Average Threshold

(in dB)

1

33

 

1.4

39

 

2

33

 

2.8

37

 

4

29

 

5.6

34

 

8

38

 

11.3

35

 

16

41

 

22.9

41

 

32

42

 

 

 

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

—

—

50

—

—

40

—

15

30

—

—

 

 

Additional Parameters:

Body weight = 180 kg

Functional interaural distance = ???? 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, 1971.

 

 

Audiogram of the harp seal in water (Pagophilus groenlandicus)

 

Data from: Terhune, J.M., and Ronald, K. (1972) The harp seal Pagophilus groenlandicus (Erxleben 1777). III. The underwater audiogram. Journal of Canadian Zoology, 50, 565-569.

 

Absolute thresholds (in dB re 2 ľN/m2) for a harp seal in water

 

 

Frequency

(in kHz)

Average Threshold

(in dB)

.760

15

 

1

16

 

1.4

7

 

2

7

 

2.8

6

 

4

13

 

5.6

12

 

8

7

 

11.3

7

 

16

9

 

22.9

5

 

32

12

 

44.9

14

 

55

19

 

64

41

 

90

52

 

100

94

 

 

 

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

—

94

60

—

91

50

—

85

40

—

63

30

—

59

 

 

Additional Parameters:

Body weight = 180 kg

Functional interaural distance = 120 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, 1972.

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.