Mysterious night-time pulsing sound

Over the last few months, I’ve occasionally heard a strange sound coming in through my open window at night. It’s a distant electronic pulsing sound which comes and goes on the wind. It seems to be coming from the north of Edinburgh around Leith. It’s quiet, but distinct. I decided to record it. The resulting recording is a bit shoddy, but it does the job.

Leith Night Pulse

I’ve no real idea what could be making this sound. Any suggestions would be welcome. It sounds to me like an alarm or an alert, like it has been designed to sound as it does. I tend to hear it around 1-3 am. Given the direction it’s coming from, it could be something happening on Leith docks or something going on at the nearby sewage works. It might even be something happening on the large cargo ships and oil tankers which often sit out in the Firth of Forth. I live maybe a mile from the coast; the way it drifts on the wind suggests that the sound source is quite far off.

Some technical details about the recording

This was a bit of a hard one because the pulsing sound was very quiet and I wanted to document it to make it clearly audible. So the approach I took was to focus on and magnify the pulsing sound at the expense of an accurate recording of the general ambience.

As it was so late at night, the ambient sound level was pretty low anyway. To get a decent level, I had to turn up the gain on my Sound Devices 702 to maximum. To reduce the effect of noise from my flat and the building, I stuck the mic (my Rode NT4 in a Rycote full modular windshield) out of the kitchen window on a fully-extended mic stand. A boom pole would have been better but I didn’t have one. I turned off the freezer in the kitchen as with the gain so high the mic was picking up a lot of the hum from that. The hum was probably louder than the pulsing sound itself. I tried to stay completely still – with the gain so high, even the tiniest sounds could be picked up. Even though I was careful, there are lots of extraneous noises in there. Little floorboard creaks, doors closing elsewhere in the building.

Annoyingly, after a few minutes the battery on my 702 died and I had neither my spare battery nor the power supply to hand. I switched to a Tascam DR100 recorder, but the preamps on that aren’t as good.

Afterwards, working with the SD702 recording, it was very quiet so I normalised it. This made the pulse louder but of course also brought up the level of all the stuff I didn’t want as well, like bass rumble and hiss. So I then did some pretty strong EQ work to remove noise at the low and high ends of the frequency spectrum. I also slightly boosted the main frequency of the pulse to bring it out of the mix a bit more. The process was very rough and ready and not at all audiophile really, but it got the result I wanted: the pulse is now clearly audible, whereas insitu it was very quiet, only just detectable over the background noise.

If this sound keeps happening, I might try a few more recordings on still nights, hopefully with a bit more care and preparation..

Vent and drain, High School Yards

Here’s a clip of a composition I’ve produced from some field recordings. Just before Christmas last year, I was recording an air vent drone in the High School Yards, to the rear of the Institute of Geography in Edinburgh. After a few minutes I noticed a regular dripping sound coming from snow melting into a nearby drain, so I decided to relocate the mic to bring both sounds into the mix.

Vent and drain clip

I think this could be a piece of experimental music; the full 6 minute version may well get released as a Buffalo buffalo track some time in the future. But it’s also a document of a hybrid micro-geography, a record of an insitu, impromptu, more-than-human performance. We could hear this as an unintended duet between the weather and the built environment, with systems for air and water management intertwining.

Many thanks to Jonathan for the photo of the air vent.

Tech details: the recordings were made with a Rode NT4 in full Rycote windshield, and a Tascam DR100 recording at 24 bit, 44.1 kHz. Recordings were edited and EQ’d in Logic..

Can you come again next week?

A great big thanks to everyone who came to Edinburgh to the international training and networking event I organised at the start of May. For those who weren’t there, this was a week-long workshop exploring experimental audio, visual and site-specific research methods. It was funded by the UK Economic and Social Research Council (ESRC), and hosted by the Institute of Geography at the University of Edinburgh, with support from the Department of Geographical and Earth Sciences at the University of Glasgow.

'Experimenting with Geography' participants and presenters

I think it’s fair to say that overall it was a big success. There was a really positive vibe about the whole thing. Eric Laurier summed up the mood in an email sent to all the attendees the following week:

“Can you come again next week? This one has lacked crackly birdsong, vibrating balloons, soldering irons, city symphonies, anechoic chambers, autumn salmon roe, centrifuges, quarry hammers, avian corpses, men on scaffolding (well it hasn’t, but has in that storyboard way), violin-voices in the foyer, cycle rides to the Wild West and most importantly, the music of your enthusiasm.”

Louise K Wilson giving a contact mic DIY session

To flesh out to Eric’s list, some highlights included:

  • A trigger-happy Matt Rogalsky wandering about shooting a starting pistol, to record the acoustics of various spaces.
  • Louise K Wilson showing people how to build their own contact mics and hydrophones (picture above)
  • Victoria Clare Bernie exploring how storyboarding might work in the context of creative research.
  • Sans Facon inviting people to compose their own sound walks.
  • Nigel Thrift giving us a big dollop of theory in the middle of the week.
  • Perdita Phillips installing mics on the roof of the geography building to record the seagulls.
  • Tansy Spinks conducting an impromptu participatory performance on the main stairs.
  • David Paton and friends presenting audio-visual work about a disused quarry which once supplied much of the stone used in Edinburgh’s grand buildings.
  • Hilary Ramsden triangulating Ennio Morricone, a side street in Morningside, and dogs barking on the meadows.
  • Hayden Lorimer describing the early history of wildlife recording, before the invention of magnetic tape. This included such things as cables running for two miles from mics in the woods to a van full of machines which would cut sound waves into discs of heated-up wax.
  • Murray Campbell from physics showing us round the acoustics labs, and answering questions such as ‘can you make a kettle boil by shouting?’ (answer: in theory perhaps, but not in practice).
  • An evening of experimental films curated by Edinburgh-based film-maker Matt Lloyd, and an evening of experimental music courtesy of Martin Parker’s Dialogues festival.

The result was a week which one participant described on his evaluation form as “by far the most interesting and fun event I had attended in the past few years”.

Eric Laurier, Tansy Spinks and a rather severe-looking gentleman
Sound absorbers in the anechoic chamber we visited

Jonathan Prior has made an audio-visual slideshow which I think nicely captures the flow of the event:

http://12gatestothecity.com/2010/05/17/experimenting-with-geography/

More documentation is available via the project discussion board:

http://michaelgallagher.co.uk/experimental-methods-network/

Special thanks to Eric, Hayden, Jonathan and Andy Wilbur for their help and support with this project, and to the ESRC for funding it.

Can you come again next week? This one has lacked crackly birdsong, vibrating balloons, soldering irons, city symphonies, anechoic chambers, autumn salmon roe, centrifuges, quarry hammers, avian corpses, men on scaffolding (well it hasn't, but has in that storyboard way), violin-voices in the foyer, cycle rides to the Wild West and most importantly, the music of your enthusiasm.

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Incidental drones

I’ve coined the term ‘incidental drones’ to describe a type of sound with which I have become fascinated over the last few years.

The definition is pretty loose. An incidental drone is just any more or less continuous droney noise, usually with a discernible pitched element, that emanates from some electrical or mechanical source which hasn’t been designed primarily to produce sound. It’s sound which is a by-product of some other function, and hence is incidental.

Incidental drones include the sounds made by:

  • Refrigerators and freezers
  • Fan ovens
  • Cooker hoods
  • Extractor fans and air conditioning systems (sound artist Eric La Casa has an album called air.ratio which is based entirely on recordings of air vents in Paris)
  • Computer fans (my own one is whirring away right now as I type)
  • Heating systems
  • Substations
  • Power tools (lawnmowers, drills, circular saws)
  • Lighting (e.g. hum from flourescent lights and dimmer switches)
  • Power lines in the mist (as described by Bill Drummond in his book 17)
  • Telephone exchange boxes
  • Generators
  • Wind turbines

In urban areas, once you start listening, you find that these sounds are everywhere. But I’ve also come across lots of incidental drones in rural areas, from grain silos, wind turbines, boat engines, fish farms and so on.

Two of the most remote places I’ve ever been in the UK had incidental drones. One was an electrical installation of some kind by the station in Corrour in the middle of Rannoch Moor in the highlands. If you’ve ever seen the film Trainspotting, this is the station they get off at to go for a walk (leading to the memorable ‘it’s sh*te to be Scottish’ speech). There are no roads anywhere near there, just a landrover track and a single rail line disappearing off across the moor.

The other was a generator in a building next to Barrisdale bothy in Knoydart, which chugged away all day. The latter is one of the most remote places in the UK. Again, no road goes near it (apparently the locals have refused offers to have one built). You can only access Barrisdale by private boat directly, by a ferry then a big walk over the Mam Barrisdale pass, or by a day’s walk over rough terrain from Kinloch Hourn, itself in the middle of nowhere at the end of a 22-mile cul-de-sac.

So I think it’s fair to say that in present-day post-industrial UK at least, these sounds seem to appear in most places where there is human habitation..

Experimenting with Geography

‘Experimenting with Geography: See-Hear-Make-Do’ is an event dedicated to developing a diverse range of craft skills associated with audio, visual and site-specific methodologies, at different city locations, both inside and out-of-doors. It will take place at the University of Edinburgh, 3rd-7th May 2010.

Applications are invited from early career researchers and PhD students to participate in this ESRC-funded International Training School.

I’m really excited about this event. We have a great line up of guests including sound artists (Jacob Kirkegaard, Matt Rogalsky), visual/site specific artists (Louise K Wilson, Sans Facon) geographers (Nigel Thrift, Trevor Paglen, Hayden Lorimer, Eric Laurier) and a visual anthropologist (Sarah Pink). It’s going to be a whole week of fun stuff. We even have some fully funded places (travel, accommodation and food costs all covered).

Check out the project page for more information and how to apply to take part:

http://michaelgallagher.co.uk/experimenting-with-geography

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