For an initial proof of concept about sound analysis and honey bee specific sound data I’ve chosen a phenomena beekeeper talking about for ages: It is a common knowledge that “normal” colonies with a queen sounds different than queenless hives.
I have checked this hundred times and did fail a dozen times while regular hive inspections. You have sometimes heavily buzzing hives, but all is ok and the queen is there and sometimes you have the opposite facts: All sounds normal but you know there is no queen in the hive. So the human ear seems not to be the best sensor for honey bee buzzing recognition.
I started recording with the phone in my hand then I placed it under the hive. The base was not solid but had a mesh, so sound recording was easy without disturbing the bees by opening the hive.
Analysis
At home I used the Sonic Visualiser http://www.sonicvisualiser.org/ to visualize the sound.
I added a so called “Peak Frequency Spectogram” and tweaked the settings a bit, in the end I got this:
I have split up some postings to the new topic Sound Visualization in case you want to see some statistics about the here discussed data have a look at this new thread:
You can find here some more sound samples from queenless and hive with queens, the file Hive1 and Hive2 is the same as in my first posting but a bit longer.
Metadata can be found in the file name.
From the visual inspection hive 4 and 6 are outstanding: Hive 4 looks like a queenless hive. the main frequency peaks around 250Hz is not so clear visible. There is a sound peak also but with a broader frequency area. Hive 6 has this band much clearer but has no queen. So it looks - from the spectrogram - like a normal hive with queen.
I can also confirm from experience that although a lot of queen-less hives do really sound different , others can (to the regular ear) sound OK … but the recordings you shared are differently interesting
Hi @clemens. I’m a software engineering student and I’m interested in the subject also I have some questions for you. What was the type of bees that were recorded? Were the hives located in the countryside or the city?
Hi @cljimene, nice to have you also on hiveeyes here! The bees are Apis mellifera carnica or a F1 or F2 generation from a Carnica hive, in the neighborhood are some Buckfast hives also so perhaps the F1 or F2 has not Carnica genes only. The hives are located in Berlin, so a city, a street is nearby, not too much traffic, but there are for sure some audio artefacts from the city in the sound data.
