Audiogram of the False Killer Whale (Pseudorca crassidens)
Data from:
Thomas, J., Chun, N., and Au, W. (1988)
Yuen, M.M.L., Nachtigall, P.E., and Breese, M. (2005) Behavioral and auditory evoked potential audiograms of a false killer whale (Pseudorca crassidens). Journal of the Acoustical Society of America, 118, 2688-2695. This is the same individual tested by Tomas et al.; authors state that “this animal probably suffered some hearing loss associated with age or presbycusis”.
Average behavioral absolute thresholds for false killer whales
Frequency (in kHz) |
Thomas et al. |
Yuen et al. |
Thomas et al. |
dB re 1 μPa |
dB re 1 μPa |
dB re 20 μPa* |
|
2 |
99 |
|
73 |
4 |
80 |
99.5 |
54 |
5 |
|
94.4 |
|
7 |
|
89.3 |
|
8 |
64 |
82.7 |
38 |
10 |
|
84.5 |
|
14 |
|
87.3 |
|
15 |
|
78.6 |
|
16 |
49 |
79.7 |
23 |
19 |
|
71.6 |
|
20 |
|
69.5 |
|
22.5 |
|
76.1 |
|
24 |
|
71.3 |
|
27 |
|
80.2 |
|
32 |
45 |
104.2 |
19 |
38 |
|
112.3 |
|
45 |
|
122.1 |
|
64 |
39.5 |
|
13.5 |
85 |
76 |
|
50 |
105 |
81 |
|
55 |
110 |
94 |
|
68 |
115 |
116 |
|
90 |
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 |
2.4 |
111 |
60 |
3.4 |
104 |
50 |
4.8 |
85 |
40 |
7.4 |
79 |
30 |
12 |
77 |
Additional Parameters:
Body weight = 18 year old animal was 700 kg (species grows to 1300 kg)
Functional interaural distance = ?? µs
(Time required for sound in water to travel through the head from one auditory meatus to the other.)
Comments: Threshold values taken from published article.
*conversion from reference level of 1 μPa used in underwater hearing to 20 μPa used in air hearing by subtracting 26 dB