Explorer Posted December 31, 2022 Share Posted December 31, 2022 Saw one researcher (Brent Stones) use the Infiltec INFRA20 infrasound monitor during a joint investigation of the Mount Wilson Ranch with "Carl the Crusher" (see YouTube link below). I have never seen this instrument before and was curious if anybody in the BF research community has used it in the field to monitor presence of infrasound. After watching Brent use this instrument (data logging the < 20 Hz frequencies detected into his laptop at different locations around the ranch, generating both DB vs. time plots and using FFT software to generate frequency spectrum plots), I am not sure how useful it will be because we don't know what exactly is generating all the infrasounds that he is detecting. Infrasound sources in the field could be wind, geological shifts, trucks moving in the distance, etc. I think Brent mentioned that even people talking and walking around the instrument could affect the sensor and generate a false signal. Brent uses this instruments in several places and is shown in multiple videos from that Mt. Wilson Ranch investigation series (besides the one I posted below), and in all places he detects infrasound. While he might conclude that there might be something paranormal in that Nevada ranch location, the more likely conclusion is that infrasound is very common and all around us. I guess you can always establish a baseline in an area and protect the instrument from wind (and rain), and then look for anomalies over the baseline. For data to be truly useful, you would have to monitor an area for a long period of time to understand how the instrument works, what a true baseline looks like, and to encode signals with known sources (thunderstorm, strong wind, truck in the forest, etc.). Looks like this instrument is available in Amazon via Infiltec for about $445. https://www.amazon.com/Infiltec-INFRA20-infrasound-Monitor/dp/B00KN1JT6W However, when I go to the Infiltec website, it does not look too professional. Maybe it is a small company. http://www.infiltec.com/Infrasound@home/ Link to comment Share on other sites More sharing options...
Catmandoo Posted December 31, 2022 Share Posted December 31, 2022 ^^^^^ Display activity for social media. Don't waste your money. We are surrounded by infrasonic noise. Infrasonic detector apps are available for free. It appears that the software for the INFRA20 has not been updated in about 10 years. Download an app. Point your phone at your powered up thermals and trail cameras and audio recorders. If you are close to a zoo that has Giraffes, you will want to visit. Giraffes have silent voices. They have bleats and grunts but they communicate with infrasound. Keep in mind that the mic(s) in your phone are not calibrated and they might vibrate / have reverberations that may affect signal processing. If you are interested and have a lot of money, buy a real, calibrated Infrasonic microphone. Beware, they hate moisture and you won't know the source of the signals. Depending on your latitude, you may get infrasonic noise from the Auroras. Download the Aurora app, its cool. People who work in the arena of infrasound have expressions for atmospheric infrasound. "Atmospheric sound zoo" and "atmospheric sound garden". For further reading, check out ELF, infrasonic communication with submarines. Link to comment Share on other sites More sharing options...
hiflier Posted December 31, 2022 Share Posted December 31, 2022 (edited) One would think that in a remote location, say, on a forestry road, that one could establish a fairly good baseline after about an hour or so. The occasional plane going over or even a mild gust of wind would show peaking but beyond that a "working normal" for the area wouldn't be that difficult to establish. And yes, I have a phone app which is interesting to use and can set a threshold line of reference for easier monitoring. Edited December 31, 2022 by hiflier Link to comment Share on other sites More sharing options...
Catmandoo Posted January 1, 2023 Share Posted January 1, 2023 4 hours ago, hiflier said: One would think that in a remote location, say, on a forestry road, that one could establish a fairly good baseline after about an hour or so. The occasional plane going over or even a mild gust of wind would show peaking but beyond that a "working normal" for the area wouldn't be that difficult to establish. And yes, I have a phone app which is interesting to use and can set a threshold line of reference for easier monitoring. Maybe yes and maybe no. The amount of time to establish a 'baseline' is not predictable. I looked at infrasonic research years ago. Some early work by Elizabeth von Muggenthaler can be viewed at the below listed site and downloading the PDF: https://asa.scitation.org/doi/abs/10.1121/1.4800658 She wrote an article about the experience. They were in a controlled indoor environment (zoo) and needed 3 days to sort out the non relevant noise. A good 'measurement mic' ( Earthworks ) can be purchased for under $1000. Parking on a remote Forest Service Road, in campsite mode, could be a good start. It goes without saying that the equipment needs to be well protected from weather. Add money and a lot of time. Link to comment Share on other sites More sharing options...
BlackRockBigfoot Posted January 1, 2023 Share Posted January 1, 2023 I have a modified version of it that can work without being attached to a computer. Naturally occurring infrasound is going to involve much weaker sound pressure waves than something that is able to cause the physical effects described by witnesses. Infrasound is all around us… but, not in levels that would cause the immediate and drastic effects that people report. Those will be noticeable if they exist at all. Versions of this device are used to detect and monitor infrasound generated by giraffes and elephants. Muggenthaler was responsible for the offhand comment about tigers using infrasound to stun their prey which caused years of misconceptions about the subject. Link to comment Share on other sites More sharing options...
Explorer Posted January 1, 2023 Author Share Posted January 1, 2023 I noticed that many folks who want to monitor earthquakes around the globe are buying the Raspberry Shake instrument instead of the Infiltec and are part of a global network of Raspberry Shake instruments. https://raspberryshake.org/ The Raspberry Shake instrument measures infrasound and is used to detect volcano activity, bolides, avalanches, landslides, tornadoes, lightning, severe storms and much more. The link below shows the unit sold for outdoors at $890 but there are other cheaper units. https://shop.raspberryshake.org/product/turnkey-iot-atmospheric-infrasound-monitor-rboom/?attribute_pa_variation=outdoor&attribute_pa_license=private-use-125-discount I recall reading some reviews comparing the Raspberry Shake to the Infiltec unit, and they yielded similar detection results. Thus, they may be comparable in sensor quality. 1 Link to comment Share on other sites More sharing options...
BlackRockBigfoot Posted January 5, 2023 Share Posted January 5, 2023 On 1/1/2023 at 12:27 PM, Explorer said: I noticed that many folks who want to monitor earthquakes around the globe are buying the Raspberry Shake instrument instead of the Infiltec and are part of a global network of Raspberry Shake instruments. https://raspberryshake.org/ The Raspberry Shake instrument measures infrasound and is used to detect volcano activity, bolides, avalanches, landslides, tornadoes, lightning, severe storms and much more. The link below shows the unit sold for outdoors at $890 but there are other cheaper units. https://shop.raspberryshake.org/product/turnkey-iot-atmospheric-infrasound-monitor-rboom/?attribute_pa_variation=outdoor&attribute_pa_license=private-use-125-discount I recall reading some reviews comparing the Raspberry Shake to the Infiltec unit, and they yielded similar detection results. Thus, they may be comparable in sensor quality. Portability would be my main concern with that unit. If you wanted to set it up stationary for long term monitoring, it would probably be ok. Even the standard Infiltec would offer more versatility, imho. Not to mention that the Infiltec units seem to be the choice of bioacousticians monitoring elephants’ use of infrasound, if that matters at all. Link to comment Share on other sites More sharing options...
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