Audiogram of the common harbor seal in air (Phoca vitulina)

 

Data from:

Mohl, B. (1968) Auditory sensitivity of the common seal in air and water. Journal of Auditory Research, 8, 27-38.one animal

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. one animal

 

Absolute thresholds (in dB re 2 ľN/m2) for three common harbor seals in air (A through C as indicated above)

 

Frequency

(in kHz)

Individual Thresholds

(in dB)

 

Average

Mohl

Kastak & Schusterman

 

 

.100

—

65.4

 

65.4

.200

—

57.2

 

57.2

.400

—

52.9

 

52.9

.800

—

26.1

 

26.1

1

36

—

 

36

1.42

34

—

 

34

1.6

—

42.8

 

42.8

2

19

—

 

19

2.8

22

—

 

22

3.2

—

30.2

 

30.2

4

26

—

 

26

6.4

—

19.2

 

19.2

8

19

—

 

19

11.25

16

—

 

16

16

26

—

 

26

22.5

58

—

 

58

 

 

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

.070*

—

60

.160

23

50

.460

20.5

40

.560

18.5

30

.720

16.9

*extrapolated value

 

Additional Parameters:

Body weight = 40 kg

Functional interaural distance= 378 ľs

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

 

Comments: Threshold values taken from Mohl, 1968, Kastak andSchusterman, 1998,

For additional thresholds for one individual, see Turnbull, S.D., and Terhune, J.M. (1990) White noise and pure tone masking of pure tone thresholds of a harbor seal listening in air and underwater. Canadian Journal of Zoology, 68, 2090-2097.

 

 

Audiogram of the common harbor seal in water (Phoca vitulina)

 

Frequency

(in kHz)

Individual Thresholds

(in dB)

 

Average

Mohl

Kastak & Schusterman

 

 

.075

—

40.3

 

40.3

.100

—

34.3

 

34.3

.200

—

22.2

 

22.2

.400

—

22.3

 

22.3

.800

—

18.2

 

18.2

1

20

—

 

20

1.6

—

5.5

 

5.5

2

11

—

 

11

4

4

—

 

4

6.4

—

1.2

 

1.2

8

3

—

 

3

16

0

—

 

0

32

-1

—

 

-1

45

8

—

 

8

64

42

—

 

42

90

56

—

 

56

128

61

—

 

61

180

69

—

 

69

 

 

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

—

180

60

—

120

50

—

78

40

.075

62

30

.125

57

 

 

Additional Parameters:

Body weight = 40 kg

Functional interaural distance= 80 ľs

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

 

Comments: Threshold values taken from Mohl, 1968, Kastak andSchusterman, 1998. Values converted from a reference level of 1 microPascal. For additional thresholds for one individual, see Turnbull, S.D., and Terhune, J.M. (1990) White noise and pure tone masking of pure tone thresholds of a harbor seal listening in air and underwater. Canadian Journal of Zoology, 68, 2090-2097.

 

For a good discussion of air and water hearing, see Kastak, D., and Schusterman, R.J. (1998) Low-frequencyamphibious hearing in pinnipeds: Methods, measurements, noise, and ecology. Journalof the Acoustical Society of America, 103,2216-2