Answers.Body: <p>The fuzzy noise near 0Hz indicates instrument noise to me at first glance. I'd zoom in much further on that to see if there is a strong fundamental frequency.</p>
  
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Answers.CreationDate: 2022-07-28T07:02:54.120Z
Answers.Text: I agree that there seems to be some low-freq noise which is coincident with the other sound, but surely we do already see a strong fundamental frequency, starting at ~150 Hz?
Answers.UserDisplayName: Dan Stowell
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Answers.CreationDate: 2022-07-28T14:12:43.540Z
Answers.Text: @DanStowell I agree the noise <150Hz is probably not the fundamental, but in my experience sometimes zooming in and changing the FFT size can make what looks like noise in higher frequencies actually resemble a super low tonal signal. Not that I am confident this is the case here, just the sort of due diligence I'd recommend to evaluate if this could be a tonal call versus noise.
Answers.UserDisplayName: Dan Woodrich
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Answers.CreationDate: 2022-07-27T18:37:15.437Z
Answers.LastActivityDate: 2022-07-27T18:37:15.437Z
Answers.UserDisplayName: Dan Woodrich
Body: <p>I am trying to learn the source of the sound in the spectrogram below. It has been recorded in early to late winter (January/February) on the shelf (25 m depth) off the US state of Georgia in the Western North Atlantic. There appears to be stacked harmonics that are frequency modulated. Audibly, they sound like they may originate from a marine mammal in my opinion. Any assistance would be appreciated.
  <a href="https://i.sstatic.net/bXp7k.png" rel="noreferrer"><img src="https://i.sstatic.net/bXp7k.png" alt="enter image description here" /></a></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-07-27T20:18:58.670Z
Comments.Text: Can you add few more details about the recording? Can you link to an audio recording so we can listen to it? Also what time of day was it?
Comments.UserDisplayName: angie_zorka
Tags: <marine-species><water><marine-mammals><mystery-sound>
Title: Mystery Marine Animal Sound off Georgia USA in Western Atlantic
ThreadText: # Mystery Marine Animal Sound off Georgia USA in Western Atlantic
  
  (Asked by: username_0 on 2022-07-27)
  
  I am trying to learn the source of the sound in the spectrogram below. It has been recorded in early to late winter (January/February) on the shelf (25 m depth) off the US state of Georgia in the Western North Atlantic. There appears to be stacked harmonics that are frequency modulated. Audibly, they sound like they may originate from a marine mammal in my opinion. Any assistance would be appreciated.
  [![enter image description here](https://i.sstatic.net/bXp7k.png)](https://i.sstatic.net/bXp7k.png)
  
  **Tags:** marine-species, water, marine-mammals, mystery-sound
  
  > **Comments:**
  > **username_1**: Can you add few more details about the recording? Can you link to an audio recording so we can listen to it? Also what time of day was it?  
  
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  ## 1 answers
  
  ### Answer by username_2 on 2022-07-27. Score: 1
  
  The fuzzy noise near 0Hz indicates instrument noise to me at first glance. I'd zoom in much further on that to see if there is a strong fundamental frequency.
  
  > **Comments:**
  > **username_3**: I agree that there seems to be some low-freq noise which is coincident with the other sound, but surely we do already see a strong fundamental frequency, starting at ~150 Hz?  
  > **username_2**: @DanStowell I agree the noise <150Hz is probably not the fundamental, but in my experience sometimes zooming in and changing the FFT size can make what looks like noise in higher frequencies actually resemble a super low tonal signal. Not that I am confident this is the case here, just the sort of due diligence I'd recommend to evaluate if this could be a tonal call versus noise.  
  
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