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..

46 Replies to “Mysterious night-time pulsing sound”

  1. Thanks Maria for your comment, and sorry for the slow reply. I’ve emailed you about this; unfortunately I’m not currently in a position to pursue further research on this at the moment as I now work in a faculty of education, so all the research I do has to align with that in some way, even if it’s tangential. I’m interested to hear how your research develops though – it’s a subject that has fascinated me for years.

    I would probably be sceptical about the microwave / 5G stuff – I’m not aware of any mechanism that would link that to low frequency noise, although that said I also have very limited training in the physical sciences, so maybe its just outside my expertise.

    Nevertheless, this is the subject on which I get the most comments on this website. Every time I come here to check the comments there are people reporting concerns and experiences. So there does seem to be a need for some sort of forum for people to discuss these issues.

    For anyone who wants to look into this issue more, the people who I’m aware of who have researched it in the most depth are Andy Moorhouse and Geoff Leventhall. There are probably others; these are two I’m aware of who are UK based, whose work I’ve found helpful for understanding the issue. They have various reports that are available in the public domain I believe.

  2. Woke up at 4:20 this night from this sound
    it vibrated through my whole body and went on for a minute or two..
    I did put my iphone on the bed to record it, i can hear the pulse faintly mainly of my bed vibrating.. I’m in Antwerp Belgium
    I live near the harbour so if it is an engine from a ship then many people would hear it i guess, it was a strange experience.

  3. I also suffer these night time pulsing sounds, almost like a heartbeat. I hear it all over the bungalow,. If I use bathroom at night I sound quite loud in there. It has only happened or rather began when two bungalows near me had modernisation done. Both properties had extensive ground work carried out. It’s driving me mad as it takeshould me ages to get to sleep and then….I need bathroom, so it starts again.
    Can anyone help, I live in Hampshire close to the coast.

  4. I also suffer these night time pulsing sounds, almost like a heartbeat. I hear it all over the bungalow,. If I use bathroom at night I sound quite loud in there. It has only happened or rather began when two bungalows near me had modernisation done. Both properties had extensive ground work carried out. It’s driving me mad as it takeshould me ages to get to sleep and then….I need bathroom, so it starts again.
    Can anyone help

  5. Late to the party. Just experienced a pulsing noise that sounded like it was travelling down the road. This was about 10 minutes ago ina Uphall, Broxburn.

  6. I live in Studio City, CA. Pandemic going on, no filming nearby and the past 5 days I’ve heard this BS. At first it was just at night, now it’s throughout the say and intermittent. There is a low grumbling, almost like someone blasting bass with windows up, then bursts that are louder. I listened to some converted space sounds by NASA and it sounds eerily similar.
    I sealed up the windows. Now, 80% of the street noise is lower, but NO CHANGE in the pulsating sound. When I try to record it nothing registers that I can see when looking at the sound waves on Adobe Audition.

  7. Excuse me Michael,
    not sure what kind of research you do, but should we please set the base of a group of scientists and other voluntary people to get very hands on this horrible mater of pulsing noises disturbing thousands of people in the UK? Also records of what people say should be listed and , with the consent of the writers, collected an analysed in a research paper to inform the government of the level of harassment going on on people property and health. From some of the research outputs, the sound is related to microwawes and infrasound. Microwaves releasing energy to air particles, could make the travel of sound faster and louder, of course this was never tested, before 5G start, as well as any other effect of the energy that 5G is going to release, unwanted, on all organisms that have no way to complain about it. In fact 5G is a matter of property , that businesses use property that is common (air) and invest various creatures nests and dwellings transferring dirty electricity that interferes with water and with their electric internal organs, without consent of all those involved. Apart from this, I spoke at Northumbria University, where I research , of taking up more research on the hum. However we need people science, we need to include people experiences, and have voluntary people interviewing and filming people, putting up documentaries, and bringing this problem to the media. The reason why I found you page is that at midnight I could not sleep because of the humming noise, I made a recording and I am sending to the council, saying ‘I am fined if I make noise’, so I expect you find the source and settle the matter. Please let in touch with myself and let’s discuss about what to do in fact and figures. I haver enough of hearing of miserable people, reporting on the internet and tortured every day in their own body and house. I want to set up this group for research. We might start as voluntary, but we can target various types of academic funding and crowdfunding. Let me know if you want to be in. Once lockdown is off, I would love to meet you and exchange some ideas in Edinburgh.

  8. i am hearing it right now as of 11:29 pm on jan 4th 2021, deep humming but pulsing sound, and it sounds like outside bc im in my room, annoying as hell, anybody know this ??? i live in the states around the ky tn area

  9. Jusst heard the loudest pulsating noises from the sky, at first thought my neighbors were pulling trashcans down the street but was entirely to loud to be that, looked outside there was no one and no cars driving by. It lasted for at least 5 minutes getting louder and lower and then just stopping. This is second time in a cpl months. Its hard to explain the sound. Perhaps more like a frieght train continuously passing over the top of your house and then just stopping.

  10. I live in Lubbock, TX (west Texas), and my 15 yr old son and I both heard it last night between 130 and 2 am. I was going to sleep and thought it was my imagination so I did not get up to investigate and neither did my son. Hopefully it will happen, again we will stay up tonight to listen for it.

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