What do the numbers associated with "Enable Amplitude Threshold Recordings" actually signify ? What is the difference between a setting of say 1000 or 20000 for instance ?
Hi Alex, Thank you very much for this info'. As it happens, about 20 minutes after posting my question I got an email informing me that AudioMoth Round 11 has been announced, it included a reference to the white paper you have so kindly provided !!!!! Had I waited a few minutes I would not have had to disturb you ! Thanks again for your always prompt and helpful replies.
I still do not understand what the numbers associated with "Enable Amplitude Threshold Recordings" actually signify ? How do I know what values to enter ?
Plus, It seems one has to tell the Config App to change to UTC+1 every time you start it up. Can this not be a set once until reset function ?
Plus, Saving the config does not save the newly entered "Advanced Settings" or the individual "Recording Periods" ?
Hi Martin,
The amplitude threshold is the amplitude threshold in terms of the WAV file sample values on a scale of 0 to 32768. For bats we use 512 or 1024 so that anything more than very quiet background noise triggers the recording.
Alex
A few reasons. The threshold is on a logarithmic scale since a change between 512 and 1024 is quite significant but a change between 10512 and 11024 probably isn't. Having a logarithmic percentage scale introduces strange interval. Also, for completeness with a percentage you'd then have to show the actual value as well. Finally, the raw value is more transparent as that is what the actual value that the AudioMoth is using to make the decision.
Yep. Have a look at the white paper here - https://github.com/OpenAcousticDevices/White-Papers/blob/master/Using_AudioMoth_with_Filtering_and_Amplitude_Threshold_Recording.pdf
Hi Alex, Thank you very much for this info'. As it happens, about 20 minutes after posting my question I got an email informing me that AudioMoth Round 11 has been announced, it included a reference to the white paper you have so kindly provided !!!!! Had I waited a few minutes I would not have had to disturb you ! Thanks again for your always prompt and helpful replies.
Martin
Further to above questions -
I still do not understand what the numbers associated with "Enable Amplitude Threshold Recordings" actually signify ? How do I know what values to enter ?
Plus, It seems one has to tell the Config App to change to UTC+1 every time you start it up. Can this not be a set once until reset function ?
Plus, Saving the config does not save the newly entered "Advanced Settings" or the individual "Recording Periods" ?
Yours
Frustrated
Hi Martin, The amplitude threshold is the amplitude threshold in terms of the WAV file sample values on a scale of 0 to 32768. For bats we use 512 or 1024 so that anything more than very quiet background noise triggers the recording. Alex
Sorry I still have no idea what the values mean - if I wanted say to filter Cetacean calls how do I know what value to use ?
Martin
If you have a recording and the interesting features have an amplitude over X% of full scale amplitude. You set the threshold to X / 100 * 32768.
The configuration read back issue slipped through our testing. We'll fix that and issue up update.
Hi Alex
Re: Amplitude threshold - forgive me but, why not just have a scale from 0% - 100% that would seem more intuitive to me ?
Re: Time zone toggle can could that be useful ?
Will look forward to Config App update.
Cheers
Martin
A few reasons. The threshold is on a logarithmic scale since a change between 512 and 1024 is quite significant but a change between 10512 and 11024 probably isn't. Having a logarithmic percentage scale introduces strange interval. Also, for completeness with a percentage you'd then have to show the actual value as well. Finally, the raw value is more transparent as that is what the actual value that the AudioMoth is using to make the decision.
Hi Alex
Thanks, ah yes that helps my poor brain to make sense of what I'm seeing !
Cheers
Martin