To test this feature, visit your live site.

Suitable adapters for Audiomoth

Hello guys,

I recently received my two Audiomoth units for Bat call recording. One is used as an "autobot" and the other is reconfigured to an USB-micophone. Both units performance very well, I am impressed by the sound quality. To be able to use the AM units with IPad och IPhones (USB-c and lightning connectors), are there any suitable adapters available and preferrably with no cable between the two interfaces.

Hope to receive suggestions, thanks!

Regards,

Mats

5 comments

5 Comments

Mats Berg

Jul 14, 2023

Alex,

Many thanks for your informative reply and files! I will definitiely try both Ultrasonic Analyzer and the AM Live App.

Also, I will elaborate with the sampling frequency to reduce the file size.

On Monday I will receive the cable for then IPad connection.

I have much to try out!

Mats Berg

Jul 13, 2023

Hello Alex,

Thank you for your reply and advice. I will look for suitable cables and adapters to make everything work properly.

Regarding the Audiomoth Live App, I just tested it and it seems to work fine. I have previously used Audacity for my initial Live Bat recordings.

Since Audiomoth and related Softwares are quite new to me, do you know if it is possible to make live recordings (bats, ultrasound) in sampel rate 384kHz and at the same time/simultaneously receive an output in the headphones of say 1/10 the frequency of the Bat call?

So far I have made recordings in sampel rate 384 kHz and when listening to the recorded Bat calls on the SD-card I have manually changed the sample rate in Audacity to 38,4kHz.

As I understand during play back this both lower the recorded Bat call frequencies to 1/10 and increase the duration of the calls 10 times.

Thanks!

/Mats

Alex Rogers

Jul 13, 2023

Replying to

Ultrasonic Analyser on the iPad works well with the AudioMoth USB Microphone and a regular USB-C to cable. It allows you to play back sound at a slower rate or to move ultrasonic sounds to the audible range in real-time. They call in 'Audio transposition' in the app.

The AudioMoth Live App uses an alternative approach and has a heterodyne bat detector included. It mixes a fixed frequency with the sound and you hear the difference in frequency between the two. You can enable the pre-recorded bat call under the 'Simulate' menu option to try this out.

This output is independent of the actual recording which will always be at the selected sample rate. We normally use 192 kHz since this is high enough for most bat calls, gives better signal-to-noise rate, and makes the files smaller. If you select 'Autosave' in the AudioMoth Live App it will record everything to WAV files in the background. You can also just click the 'Capture WAV' to capture the period currently on the screen to a WAV file. Good for interesting events that you want to capture without having to search through the autosaved files.

Here's what it sounds like.

Alex Rogers

Jul 14, 2023

Replying to

You might also find the AudioMoth Filter Playground - https://playground.openacousticdevices.info - useful. It makes it very easy to make videos and images of bat calls, including the ability to play them back at a slower speed to become audible. Not intended for live recording - that's what AudioMoth Live App is for - but great for analysis of recordings.

Alex Rogers

Jul 12, 2023

For iPad you can use a USB-C to micro USB cable and it works directly. For iPhone a lightning to USB OTG adaptor should allow you to use a regular USB cable. I haven't found any apps that support high sample rate recording though. On laptops the AudioMoth Live App works really well with AudioMoth USB Microphone - https://www.openacousticdevices.info/live. It will automatically detect the AudioMoth and sample at the true hardware sample rate.