Answers.Body: <p>Good question. I have recorded whiteflies with a laser vibrometer before. They are very quiet. I have used piezo a few times and I would agree that they have quite a big self noise but maybe in very quiet lab conditions you might be able to get descent results.
  Also where are you based? I know quite a few labs who have a laser vibrometer in Europe and the US that might be interested in collaborating.</p>
  
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Answers.Text: Thanks Cam! I'm in Kent, UK.
Answers.UserDisplayName: Noil
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Answers.Text: I believe there are teams working with laser vibrometers in the University of Lincoln (Dr. Montealegre-Z), Bristol (Dr. Robert) or Strathclyde (James Windmill).
Answers.UserDisplayName: Cam Desjonqu
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Answers.UserDisplayName: Cam Desjonqu
Answers.Body: <p>I've tried with several piezo sensors &quot;for guitar&quot; (2.5cm diameter; frequency and impedance characteristics not available; <a href="https://www.amazon.co.uk/gp/product/B083LS5MGT/" rel="nofollow noreferrer">seller page</a>) and I got no signal at all. I stuck the whole piezo to the leaf (as advised in the responses of this <a href="https://bioacoustics.stackexchange.com/questions/1024/how-best-to-attach-piezzo-sensors-to-a-leaf-to-measure-insect-vibratory-signal">SE question</a>) and amplified the signal with the preamp of a sound interface (+62 dB, <a href="https://motu.com/products/avb/stage-b16/specs.html" rel="nofollow noreferrer">Motu STAGE-B16</a>). Whiteflies were beneath the leaf and did produce their tremors (recorded with an air microphone, following a similar method to Kanmiya 2006).</p>
  <p>I don't know whether these piezos were sensitive enough for such tiny sounds though.</p>
  <p>Spectrogram of piezo sensor (top) versus air-pressure mic (bottom):
  <a href="https://i.sstatic.net/bYkPd.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/bYkPd.png" alt="enter image description here" /></a></p>
  
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Answers.Text: What type of pre-amp did you use? piezo need FET based pre-amp for impedance matching
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Answers.Text: @WMXZ The piezo came with a mono jack plug which I plugged to the mic input of a Motu STAGE-B16 sound interface (pre-amplification of +63 dB).
Answers.UserDisplayName: Noil
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Answers.Text: With a laser vibrometer I was getting sounds from the stem and they were under the leaf... Sorry I can't be more helpful with the  piezos!
Answers.UserDisplayName: Cam Desjonqu
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Answers.Text: @CamDesjonqu whaouu, so it is more powerful than what I thought
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Body: <p>Whiteflies communicate before and during mating through abdomen oscillations which vibrations are believed to  propagate mostly in the leaf (~100-400 Hz). They are very low-energy signals which are subject to low signal-to-noise ratio when recording them.</p>
  <p>Gold-method to record substrate vibrations (<a href="https://doi.org/10.1007/978-3-030-97419-0_8" rel="noreferrer">ref</a>), and  as in the most recent <a href="https://doi.org/10.1038/s41598-021-85904-0" rel="noreferrer">study</a>  about whitefly vibration communication, is the the use of laser vibrometer. However, I don't have any. I have two possibilities:</p>
  <ol>
  <li><strong>Microphone.</strong> One of the world-leading team working on whitefly vibratory communication put the edge of the subtrate leaf in contact with a paper which acts as a diffuser to amplify the diffused vibration to the air; then they use a microphone to pick the sound in the air. It looks like it requires a great deal of fineness to be sure that the leaf is well &quot;connected&quot; to the paper (whiteflies are pest that usually cannot be handled freely, so it adds some practical difficulty)</li>
  </ol>
  <p><a href="https://i.sstatic.net/WcV7q.png" rel="noreferrer"><img src="https://i.sstatic.net/WcV7q.png" alt="enter image description here" /></a>
  Kanmiya, Kenkichi (2006), Mating Behaviour and Vibratory Signals in Whiteflies (Hemiptera: Aleyrodidae), in Sakis Drosopoulos and Michael F. Claridge (Ed.), Insect sounds and communication : physiology, behaviour, ecology, and evolution.</p>
  <ol start="2">
  <li><strong>Piezo.</strong> This <a href="https://doi.org/10.1007/978-3-030-97419-0_8" rel="noreferrer">paper</a> about low-cost methods to record substrate vibrations advises piezoelectric sensors, and their frequency response is adequate to my application. However, I've never seen any papers about whitefly recordings using piezo sensors.</li>
  </ol>
  <p>I'd like to try the piezo method, as it would be easier for me to stick a piezo to the leaf rather than to design the great setup above. The piezzo has a greater self-noise but it measure the vibration directly, while I have very good low-noise microphones but the vibro-acoustic transduction between the leaf and the air will decrease the signal intensity.</p>
  <p>Do you have any experience in this and what would you recommend between the two in term of signal-to-noise ratio?</p>
  <p>PS: this question is not about the technics to attach the piezzo for which I made a specific <a href="https://bioacoustics.stackexchange.com/questions/1024/how-to-attach-piezzo-sensors-to-a-leaf-at-best">question</a></p>
  
Tags: <recording><noise><microphone><insect><vibrometer>
Title: Recording of whitefly vibrations: "piezo" versus "low-noise microphone with subtrate-air diffusion"
ThreadText: # Recording of whitefly vibrations: "piezo" versus "low-noise microphone with subtrate-air diffusion"
  
  (Asked by: username_0 on 2022-08-07)
  
  Whiteflies communicate before and during mating through abdomen oscillations which vibrations are believed to propagate mostly in the leaf (~100-400 Hz). They are very low-energy signals which are subject to low signal-to-noise ratio when recording them.
  
  Gold-method to record substrate vibrations ([ref](https://doi.org/10.1007/978-3-030-97419-0_8)), and as in the most recent [study](https://doi.org/10.1038/s41598-021-85904-0) about whitefly vibration communication, is the the use of laser vibrometer. However, I don't have any. I have two possibilities:
  
  1. **Microphone.** One of the world-leading team working on whitefly vibratory communication put the edge of the subtrate leaf in contact with a paper which acts as a diffuser to amplify the diffused vibration to the air; then they use a microphone to pick the sound in the air. It looks like it requires a great deal of fineness to be sure that the leaf is well "connected" to the paper (whiteflies are pest that usually cannot be handled freely, so it adds some practical difficulty)
  
  [![enter image description here](https://i.sstatic.net/WcV7q.png)](https://i.sstatic.net/WcV7q.png)
  Kanmiya, Kenkichi (2006), Mating Behaviour and Vibratory Signals in Whiteflies (Hemiptera: Aleyrodidae), in Sakis Drosopoulos and Michael F. Claridge (Ed.), Insect sounds and communication : physiology, behaviour, ecology, and evolution.
  
  2. **Piezo.** This [paper](https://doi.org/10.1007/978-3-030-97419-0_8) about low-cost methods to record substrate vibrations advises piezoelectric sensors, and their frequency response is adequate to my application. However, I've never seen any papers about whitefly recordings using piezo sensors.
  
  I'd like to try the piezo method, as it would be easier for me to stick a piezo to the leaf rather than to design the great setup above. The piezzo has a greater self-noise but it measure the vibration directly, while I have very good low-noise microphones but the vibro-acoustic transduction between the leaf and the air will decrease the signal intensity.
  
  Do you have any experience in this and what would you recommend between the two in term of signal-to-noise ratio?
  
  PS: this question is not about the technics to attach the piezzo for which I made a specific [question](https://bioacoustics.stackexchange.com/questions/1024/how-to-attach-piezzo-sensors-to-a-leaf-at-best)
  
  **Tags:** recording, noise, microphone, insect, vibrometer
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_1 on 2022-08-26. Score: 3
  
  Good question. I have recorded whiteflies with a laser vibrometer before. They are very quiet. I have used piezo a few times and I would agree that they have quite a big self noise but maybe in very quiet lab conditions you might be able to get descent results.
  Also where are you based? I know quite a few labs who have a laser vibrometer in Europe and the US that might be interested in collaborating.
  
  > **Comments:**
  > **username_0**: Thanks Cam! I'm in Kent, UK.  
  > **username_1**: I believe there are teams working with laser vibrometers in the University of Lincoln (Dr. Montealegre-Z), Bristol (Dr. Robert) or Strathclyde (James Windmill).  
  
  ---
  
  ### Answer by username_0 on 2022-09-04. Score: 0
  
  I've tried with several piezo sensors "for guitar" (2.5cm diameter; frequency and impedance characteristics not available; [seller page](https://www.amazon.co.uk/gp/product/B083LS5MGT/)) and I got no signal at all. I stuck the whole piezo to the leaf (as advised in the responses of this [SE question](https://bioacoustics.stackexchange.com/questions/1024/how-best-to-attach-piezzo-sensors-to-a-leaf-to-measure-insect-vibratory-signal)) and amplified the signal with the preamp of a sound interface (+62 dB, [Motu STAGE-B16](https://motu.com/products/avb/stage-b16/specs.html)). Whiteflies were beneath the leaf and did produce their tremors (recorded with an air microphone, following a similar method to Kanmiya 2006).
  
  I don't know whether these piezos were sensitive enough for such tiny sounds though.
  
  Spectrogram of piezo sensor (top) versus air-pressure mic (bottom):
  [![enter image description here](https://i.sstatic.net/bYkPd.png)](https://i.sstatic.net/bYkPd.png)
  
  > **Comments:**
  > **username_2**: What type of pre-amp did you use? piezo need FET based pre-amp for impedance matching  
  > **username_0**: @username_2 The piezo came with a mono jack plug which I plugged to the mic input of a Motu STAGE-B16 sound interface (pre-amplification of +63 dB).  
  > **username_1**: With a laser vibrometer I was getting sounds from the stem and they were under the leaf... Sorry I can't be more helpful with the  piezos!  
  > **username_0**: @CamDesjonqu whaouu, so it is more powerful than what I thought  
  
  ---
  
  