Skip to content


If we could shrink ourselves to microscopic size, what sounds would we hear?
Microbes is the (fictional) answer to that question.

The idea for this library came from thinking about foley and sound design for nature documentaries, and, in a reverse way, was also inspired by the many libraries of monster sounds already in existence. Why not turn from huge, hulking monsters, to tiny creatures - they could even be actual, existing specimens; not the fantasy/sci-fi variety? Maybe like this?

But of course, the problem of designing sounds for creatures that have never been heard by a human being; that may in fact not have any kind of voice or way of affecting their surroundings enough to move air molecules in any substantial amount - that seemed a tricky task.

Design space - framing the problem:
Going about the work in bursts of experimentation (followed by long periods of mulling things over), I eventually arrived at a frame for what I wanted to do:

  • Specifics of creatures doing things like eating, vocalizing and moving about. Diegetic sounds, if you will.
  • Mood-setting ambiances, not immediately related to any creatures, but of the sort I personally would expect to be used for creating an atmosphere of an alien world - like the microscopic realm. Non-diegetic sounds, then.

Tools used - and how they affected results:
Having done more field recording than studio-based sound design in the past, I started with a fairly blank slate in terms of tools and techniques.
On the other hand, I had some sort of repertoire of sounds - acquired while working with my modular synthesizer. Cross-modulating the fm-inputs of two VCO's while tweaking the tuning knobs was one favorite - LFO modulation of filter cutoff to get bubbling sounds was another. These became the starting points for many of the skittering, chattering sounds heard in the library.

One of my references was the comical "bubble-engine" sound from a car driven by bees in the animated "Bee-Movie" - a fave of my kids. It made sense to me as some sort of bacterial propulsion sound (tiny fluttering cilia or something like that). However, I couldn't seem to nail a performance I liked with the synth. Where others might have fired up MAX/MSP, I fired up my favorite tools; a couple of mics. I chose to use my DIY Primo EM172 omni's (as seen in the picture) for three reasons:

  1. I knew they have frequency response beyond 20 kHz (though not remotely linear) - important for anyone wanting to pitch down the sounds later on.
  2. They would be much easier to move around during the session since I would keep them on their Gorillapod's and plug them directly into my portable recorder.
  3. If they got wet, it would be no big deal.

Mounting them to a bucket of water, I proceeded to blow bubbles through pipes of various diameters, as well as releasing air from bottles and jars. Bubbles galore.

For other crawling, skittering sounds, as well as wetter, slimier things, I stuck with the mics - and stuck them everywhere: from a long-spiked cactus, mouth. I brought my MKH mics in this time, although I kept them out of my gob. I hadn't planned to get into voice-acting microbes, but I guess some career choices just happen like that. Having recorded most of the specifics, I didn't have exactly what I wanted going in, but I did rather like what I found instead. As so often happens, your choice of tools influence what you build with them.

For the ambient sounds, my point of departure was two-pronged: I coaxed something wibbly-wobbly from the modular and had fun with a cello-bow and a little thing I put together from Luxo-lamp springs, an empty rack case and a few nuts and bolts (see picture). Plenty of rosin on the bow, then stroking diagonally across the springs at various points along their length, produced different kinds of metallic shrieks and groans, with acoustic reverb courtesy of that metal case. All going into contact mics. Much fun.

Mixing & mangling:
I like working in a DAW, but I prefer to source my sounds outside of one. Composing music or designing sounds in-the-box always felt like; I don't know - playing a drum kit through a key-hole or something. But once I've got something, a source-sound, then I like the feel of editing and processing in the DAW.

In the case of these particular sounds, I needed to make the ambiances more ambient, and the specifics more alien. Messing with weird reverb chains and the wonderful plugins from Soundhack was part of it; making the specifics more believable was another. Delaying, duplicating and offsetting audio items helped on some sounds. On others, it was those little things that give away a sound as originating from a human that I needed to get rid of: breathing, smacking and smecking, the click of fingernails or just a certain rhythm, recognizable by anyone with arms who ever tried playing any kind of instrument - whether bowing, striking or scraping it. I also realized that there would be no room-tone to these sounds; since they would be emitted in water or other fluids. One move solved most of these problems, as I discovered that running many of the sounds through iZotope RX on "ham-fisted, all-thumbs" mode gave them that dull, anechoic, slightly wobbly quality I was looking for. Some sounds, I opted not to treat that way, as I felt it dulled them too much and took some of the malleability out of them for the sound-designers. Feel free to pummel these sounds with a de-noiser if you like.

Wrapping up...
So there you go; microbial audio for your pleasure.

Stay tuned for the release of Microbes!

MKH60/30 M/S Combo
One of the things which set sound effects recordists apart from many other professionals who record sound, is the special requirements we have for the gear we use. Case in point: microphone frequency response. I don't know how many online recording-related discussions have been derailed the moment someone asks about the feasibility of 192 kHz recording and ultrasonic capability of certain microphones as means for better sounding recordings. Countless hapless n00bs have been told off about the limits of human hearing and the dismal frequency response of most speakers and headphones. I usually pull out before it goes all tar-and-feathers; I can no longer be bothered piping up about sound design and pitch manipulation.

Most microphones supposedly useful in pro audio are not spec'ed for ultrasonic capture. Googling the phrase "ultrasonic microphone" mostly yields bat-detectors and components for 3D positioning. Famous exceptions are the Sanken CO100 and the MKH80x0 series. But maybe spec sheets don't tell the whole truth. Enter cheap electret capsules. After reading this article on a DIY solution to ultrasonic recording using Panasonic capsules, I looked at my portable Sony PCM M10 with fresh eyes. Would it's internal mics (supposedly Primo EM 172's) also be capable of ultrasonics? The datasheet isn't much help - it looks like someone took a wild guess with a pencil and a ruler. But then it dawned on me that both Earthworks and DPA use electrets in mics capable of beyond 20kHz recording. What about true condensers like the MKH series?

Ok, so It wasn't the most linear train of thoughts I have ever had, but I basically decided to test my hypothesis that ultrasonics were not a selling point when the original MKH series came out, and so was ignored in the specs. I wanted to know if my MKH60/30 combo might have that much coveted extended response.

Enter the key-jangle test.
A big reason for wanting the really hi-freq stuff is to record metal objects and then pitch those sounds down in post - it's a great way to design huge mechanical sounds that don't sound strangely dull when their pitch is lowered. So for that reason, a good test might be to jangle a few steel keys (and similar objects) in front of the mic:

This was recorded using the MKH60, at 96kHz sampling frequency. Loading it into iZotope RX, we see a lot of high-frequency action going on:
Spectrogram of key jangle test

Zooming in, it becomes obvious that those vertical spikes (the keys hitting each other) go all the way up to 40kHz and beyond. Since the brightest areas in this spectrogram correspond to the loudest frequencies, it's clear that most of the energy lies between 8-20kHz, but the sound doesn't exactly drop off dramatically in the frequencies above that:
Zoomed in on ultrasonic frequencies

Here's a clip of the same recording slowed down to a quarter of it's original speed:

Not shown (or heard) in these clips is the response of my MKH30 which was also recording at the time. Being setup in M/S, it was off-axis to the source, which would attenuate the higher frequencies to begin with, but even then there was still quite a bit going on over 20kHz (you'll have to take my word for it).
So if you own a mic from the old MKH series, you can perhaps forget your 80x0 envy for a while; at least as pertains to ultrasonic recording.

ABB robot
Earlier this year, I got the opportunity to record at a local educational institution; distinguished by the fact that it operates a number of labs and workshops containing some pretty interesting equipment:

  • A fleet of 3D-printers
  • Several industrial robots
  • Various other CNC-machines

Members of the staff there were kind enough, not only to allow me in, but also to operate the gear I wanted to record.
Do I need to say I was excited?
Of course, being an educational environment, it was there for the sake of the students - not me. This is the well-known problem always facing field-recordists; to be cheeky enough to get the sounds we want, without bothering people.

I started out in a small room containing 3 or 4 Ultimaker 2 3D-printers, of which 3 were running at the time. Many people will have heard the sounds of this type of machine, but to get 3 of them printing in the same room, with a heavy door between me and the rest of the workshop, was more than I had hoped for.
'Twas a symphony of plastic filament meltage - I swear I heard traces of a be-bop saxophone solo in that cacophony!
Have a listen:

Next up was a large, bright orange ABB IRB 6620 industrial robot - the kind you see in footage of car factories. It was located in a room of its own, which I suppose is for safety reasons and the fact that it had a fan running of some kind, which was rather noisy. I couldn't quite get the clean sounds of just the robot moving, not least because of a safety measure which prohibited movements beyond a certain (slow) speed while under manual control. It was possible to pre-program it to move faster, but then it would against the lab rules to stay in the room with the robot. Like the man said: "It could easily punch a hole in the ceiling". I became somewhat disinclined to stand at the business end of a 10-foot steel arm able to do that.
For all that, I did get some sounds that certainly sound industrial in nature:

Luckily for me they also had the smaller ABB IRB 120 robot there. This time, there was no fan noise and less safety measures. We did a bunch of single-axis movements, as well as more complex things. I suppose we all have an idea of how servos sound (think gigantic sci-fi robots), but the real deal had more to offer that I had expected. Not just the whirring and whizzing, but also little jittery, buzzing sounds - especially when the machine was idling:

Lastly, I got close to a Z√ľnd flatbed CNC cutter. This thing cuts the finest patterns into sheet materials like plastic and paper, using a tiny, sharp blade.
Again, lots of interesting whizzing and jittery sounds. Especially the calibration procedure sounded cool:

Naturally, I didn't just record these machines out of my own curiosity - but to be able to deliver their sounds to you, dear reader.
Expect them out soon; sign up for the mailing list to get a substantial release discount, and while you wait, listen to this preview:

Out now - Robotics Lab!

Here's the next sound effects library from Hzandbits - it's called Vibration.
These are nearly a hundred sounds (most of them seamless loops) created with various metal/plastic boxes and panels - and a 100w tactile transducer.
Have a listen:

Fittingly for this season, I'm just now finishing a library of very windy sounds. I've done plenty of those before, but this time, the focus is on wind through vegetation. Trees, bushes, grass and reeds get a solid stir during Danish winters, and that is what Wind In Trees is made of:

The focus is rather narrow, going for many nuances of the same flavor - rather than many flavors. If you need sounds of a storm or gale in northern European vegetation, then this should fit the bill. Note that there is audible buffeting in several files. I opted to leave it in there, as it might suit some purposes, and let me keep the most violent passages. You can try your luck with noise reduction, but since wind is mostly broadband noise anyway, it might not turn out well. YMMV.

Out very soon...