Orca Acoustics

Listen Live

There are several hydrophones live-streaming throughout the inland waters of Washington, so no matter where you live you can tune in and listen for whales! From a computer, you can record what you hear using the free, open source software Audacity, which works across all operating systems.

Orcasound.net

Go to the link above and click “Listen Live” to select from three hydrophones:
Bush Point (off SW Whidbey Island)
Port Townsend
Orcasound Lab (a couple miles north of Lime Kiln in Haro Strait)

Lime Kiln Hydrophone

Hosted by SMRU Consulting and The Whale Museum, the link above will take you to the live audio stream, or you can also tune in while viewing the PTZ camera mounted on the Lime Kiln lighthouse.

Point Robinson Nearshore Cam

Hosted by Sound Action, this combination underwater webcam and hydrophone is positioned just off the Point Robinson Lighthouse on Maury Island in southern Puget Sound.

Orca Vocalizations

Orcas make three primary types of vocalizations: clicks, whistles, and discrete calls. Clicks, or echolocation, are used by the whales to navigate and forage. Whistles are the primary social vocalizations for most dolphin species; orcas use them in social communication as well, but they are relatively rare compared to discrete calls. Discrete calls are short (1-2 second) tonal vocalizations with distinct harmonic structure.

Different social groups of orcas use different repertoires of stereotyped discrete calls, making it possible to identify which populations or sub-populations of orcas are present based on acoustic data alone. For example, the Southern Residents, Northern Residents, and Bigg’s killer whale populations that have an overlapping geographic range all sound acoustically distinct. Within the Southern Residents, while some call types are shared across pods, J-Pod, K-Pod, and L-Pod can also be distinguished acoustically.

Just like the whales themselves, killer whale whistles and discrete calls are given alphanumeric designations: S1, S2, etc. for discrete calls and SW1, SW2, etc. for whistles You can find the original catalogue of discrete call types for Northern and Southern Residents and Bigg’s killer whales (transients) published by John Ford in 1987 at this link. Spectrograms of Southern Resident killer whale whistles can be found in OBI’s 2021 paper by Souhaut and Shields.

Southern Resident killer whale whistle SW2

Southern Resident killer whale echolocation

Southern Resident killer whale discrete call S2

Identify J-Pod

J-Pod’s most common call type is the S1:

S1s

Some of their other common call types – such as S3, S7 S12, are similar in structure, with multiple descending notes:

The four calls in this sound clip are S12, S7, S12, and S3

Another common J-Pod call, often characterized as sounding like a sheep or a goat, is the S4. Other pods to occasionally make this call too, but if you hear a bunch of S4s, it’s almost certainly J-Pod:

S4s

Identify K-Pod

K-Pod is distinct with their high-pitched, kitten-like calls, S16 and S17:

S16s
S17s

Identify L-Pod

L-Pod has two distinct acoustic groups. The L12 sub-group can be readily identified by their usage of the S2iii (read as “S2 type 3”) call:

S2iii from the L12 sub-group of L-Pod

The most common call for the rest of L-Pod is the S19:

SRKW Superpod Clip and Pod Quiz

You’ll hear the above call types and many others in this short superpod clip. It’s hard not to smile when hearing vocalizations like this! If you enjoy this one, you can check out a highlight reel of some of other favorite recordings over the years on our Soundcloud.

A Southern Resident killer whale superpod, which sounds a lot like the social party it is when all members of J-, K-, and L-Pod get together

Below you’ll find three two-minute recordings, one from each pod. Using what you learned above, can you figure out which pod you’re hearing in each one? Answers are at the bottom of the page.

Quiz #1
Quiz #2
Quiz #3

Other Species Heard on the Hydrophones

The hydrophones don’t just pick up Southern Resident killer whales, but also anything else audible underwater. Often, you will hear long stretches of engine noise from a passing freighter, or the louder but briefer transiting of a smaller vessel. Sometimes you can even hear wave action or rain! Most exciting though is to detect other marine mammals.

If you listened to the above clips of Southern Resident discrete calls, you’ll hear an immediate difference in the vibrato calls that are distinct for Bigg’s killer whales:

Bigg’s killer whale discrete calls

Bigg’s killer whales aren’t nearly as vocal as Southern Residents, but as their presence in the Salish Sea has increased, they are detected more often on the hydrophones. They are most likely to vocalize after a hunt or when in multi-family social group.

Bigg’s killer whales aren’t the only population that has increased in the Salish Sea; after nearly 100 years of being hunted to local extinction, humpback whales have also returned. Beginning in 2013, humpback whale song fragments and phrases have been heard on the hydrophones, most often in September-December.

Humpback whale in Haro Strait December 2019

Finally, every year we also get questions about this “heavy breather”, heard after dark on the Haro Strait hydrophones. While usually silent underwater, this is actually a territorial vocalization from a male harbor seal!

A territorial vocalization from a male harbor seal

Quiz Answers:
#1 – K-Pod
#2 – L-Pod (L12s)
#3 – J-Pod

Did you find this acoustic tutorial helpful? If so, please consider making a donation of $5 or more to us to help us cover the maintenance costs of our acoustic equipment so we can keep making orca recordings in the field!