<p>Were you able to get a bearing on them?  As in did the sounds appear on all hydrophone channels.  Did the time difference make sense, even if on axis?  It reminds me of the array sliding through mystery stuff, making physical contact as whatever it was slid along the array, past the hydrophones, or elicited acoustic response from fish.  These are some items to check off the list at least.</p>

CC BY-SA 4.0
2022-07-06T13:46:38.880Z
Unfortunately, this recordings are saved on taped drives (!!!) and I do not readily have access to the original data to check; however, I have more experience than I would like listening to sounds touching the array (seaweed, xbt wire, fishing gear, waves) and this is uncharacteristic of this type of sound. While it is entirely possible this is a fish-- the instruments were typically at 5-10 m depth, but the environment was abyssal (so, this would have to be a pelagic fish).
Shannon
CC BY-SA 4.0
2022-07-06T00:39:49.493Z
2022-07-06T00:39:49.493Z
Jeff K Jacobsen
<p>What is this sound from offshore Peru? I recorded this sound offshore Peru and called it the “pacman” sound for obvious reasons. This was recorded from a towed hydrophone array from a large scale shipboard survey and only heard for a few minutes. We conducted sparse transects through this region for several years and surveyed throughout the Eastern Tropical Pacific for &gt;5 years and I have never heard this sound outside of this one encounter.</p>
<p>Does anyone know what this is? Audio available on <a href="https://soundcloud.com/southwestacousticecology/mysterypacman-rankin-swfsc-star2003" rel="noreferrer">Soundcloud</a> and spectrogram provided:
<a href="https://i.sstatic.net/YXwQl.png" rel="noreferrer"><img src="https://i.sstatic.net/YXwQl.png" alt="Spectrogram of Unknown &quot;pacman&quot; sound recorded off Peru" /></a></p>

<marine-species><identification><mystery-sound>
Unknown upswept pulsed sound recorded offshore Peru
# Unknown upswept pulsed sound recorded offshore Peru

(Asked by: username_0 on 2022-07-05)

What is this sound from offshore Peru? I recorded this sound offshore Peru and called it the “pacman” sound for obvious reasons. This was recorded from a towed hydrophone array from a large scale shipboard survey and only heard for a few minutes. We conducted sparse transects through this region for several years and surveyed throughout the Eastern Tropical Pacific for >5 years and I have never heard this sound outside of this one encounter.

Does anyone know what this is? Audio available on [Soundcloud](https://soundcloud.com/southwestacousticecology/mysterypacman-rankin-swfsc-star2003) and spectrogram provided:
[![Spectrogram of Unknown "pacman" sound recorded off Peru](https://i.sstatic.net/YXwQl.png)](https://i.sstatic.net/YXwQl.png)

**Tags:** marine-species, identification, mystery-sound


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## 1 answers

### Answer by username_1 on 2022-07-06. Score: 1

Were you able to get a bearing on them? As in did the sounds appear on all hydrophone channels. Did the time difference make sense, even if on axis? It reminds me of the array sliding through mystery stuff, making physical contact as whatever it was slid along the array, past the hydrophones, or elicited acoustic response from fish. These are some items to check off the list at least.

> **Comments:**
> **username_0**: Unfortunately, this recordings are saved on taped drives (!!!) and I do not readily have access to the original data to check; however, I have more experience than I would like listening to sounds touching the array (seaweed, xbt wire, fishing gear, waves) and this is uncharacteristic of this type of sound. While it is entirely possible this is a fish-- the instruments were typically at 5-10 m depth, but the environment was abyssal (so, this would have to be a pelagic fish).  

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