Hello. So I thought the audiomoth has a directional microphone but it appears from a post below that its omni. But my question is what does this really mean since its housed in a box? Does it have a 180 degree field of hearing? Can it hear behind it at all where the batteries and cases may block sound? How do I achieve 360 field of hearing? Will i get this from one audiomoth or since the way the microphone is housed is it really only directional? I ask because I am working out detection distance for my species and so I need to work detection space from this. My species is a primate so I'm wondering if I face it up to the trees then do i get equal sensitivity in all directions?
Thank you
Hi Saul, I'm not sure where the study was published in the end. Probably best to follow up with Ella Browning at UCL (ella.browning.14@ucl.ac.uk) who did the comparison. Alex
Hi Alex,
This URL doesn't appear to be working for me. I am interested in this information as I am currently undertaking a research project using AudioMoths. If you could provide a new link or any information about where to find the study about the directionality and sensibility of AudioMoths it would be very helpful.
Many thanks
Saul
Hello, the link to the website including the deployment protocol does not work. I am very interested how you determined the sensitivity and what kind of cases you have used. Could you write the actual link into the Support Forum again if possible, please?
Thank you very much.
Thank you so much!
Hi, The microphone itself is omni-directional in the plane of the PCB but the PCB, the batteries, and any housing will introduce some directionality. There aren't many results on this but we did a citizen science project with University College London and the Bat Conservation Trust last summer and made some sensibility comparisons with other detectors. You'll find a description of the deployment protocol (including the description of the cases used) here - https://britishbatsurvey.com/taking-part-in-the-pilot/. The sensitivity was tested with an artificial bat generating the results below.
In this setting, the case definitely makes the device more directional. That may be because the frequency is very high and the case has a small aperture. You'll probably need to test your set-up with some sort of test recording to really evaluate this properly. If you face the device upwards (rather than toward a fixed direction as in the case here) I suspect you will get very close to omni-directional coverage.