--- title: "One Sound File, Seven Countries. Nine Of The Rest Were Machines." dek: "Of 1,142 recordings collected over eleven years from thirty-one countries, 1,009 are the same 43-second audio file, licensed from a commercial sound library. We geolocated 41 of the remainder and found a source for nine." kind: analysis (Analysis) desk: Cryptids author: Sal Brindisi and Dev Rajagopal (fictional) published: 2026-08-22T12:30:00Z url: https://theyburied.com/article/sky-trumpets-one-waveform tags: sky trumpets, audio forensics, sound libraries, cross-correlation, Silesia genre: satire status: fiction — nothing in this story happened; every person, source and document is invented --- # One Sound File, Seven Countries. Nine Of The Rest Were Machines. *Of 1,142 recordings collected over eleven years from thirty-one countries, 1,009 are the same 43-second audio file, licensed from a commercial sound library. We geolocated 41 of the remainder and found a source for nine.* One thousand and nine of them are the same forty-three seconds. That is the result of taking every recording of the low metallic groaning called sky trumpets that this newspaper has been sent in eleven years — 1,142 of them, from thirty-one countries — and correlating every one against every other one. Eighty-eight per cent of the corpus is one audio file. > **Figure:** What 1,142 uploads turned out to be — see https://theyburied.com/article/sky-trumpets-one-waveform ## How we did it We collected for eleven years and published nothing, because a recording on its own cannot be checked against anything. In February the corpus was large enough. We stripped every filename, timestamp and metadata field and handed the audio to Dr. Yusra Lindqvist-Achike, an audio forensics researcher in Delft, without telling her what it was supposed to be. The instruction was one line: correlate everything against everything. She returned a matrix with a single enormous cluster in it, and a note asking whether we had accidentally sent her the same file a thousand times. ## Eight generations of copying Every time a clip is re-uploaded it is re-encoded, and the damage that leaves is cumulative and directional. That is why a chain of copies can be read backwards. We counted eight generations between the most degraded uploads and the cleanest. At the top of the chain sits a licensed cue in a commercial sound library — catalogue number 4413-07, "Metal Groan, Distant", on sale since 2010 for sixty euros. We found it because the library requires attribution, and a truncated credit string survives in the metadata of 214 of the copies. The clause that people complain about is the clause that made this story reportable. In seven countries we can put the whole chain in order, copy by copy, with a dated upload at every generation. In the other twenty-four we have the file and we do not have the route. Our headline says seven for that reason and the public editor's objection to it is printed below. ## What the cue actually is It is a recording of a brake on a mine winding engine in Upper Silesia, made in the rain at ten past three in the morning on 14 November 2009 by a field recordist named Ansel Kirchmayr-Bello, who was standing two hundred metres away with a commission for industrial atmospheres. It is not synthetic. It is not a hoax. It is a real machine, recorded once, extremely well. > They were not listening to a synthesiser. They were listening to Poland. > > — Ansel Kirchmayr-Bello ## The hundred and thirty-three That leaves 133 recordings that are not the file. Something happened near those microphones. We geolocated 41 of them, using clock chimes, church bells, weather at the stated time, and in eleven cases an aircraft passing overhead that could be matched to a published flight track. Of those 41 we found a source for nine, by the unglamorous method of telephoning the nearest heavy industry and asking what makes a noise. Two are mine hoist brakes, one of them ninety kilometres from the one on the cue. One is a flare stack at a refinery, on a night the plant logged an unplanned depressurisation. Three are thermal expansion in the steel deck of a lift bridge, all three on rising temperature gradients, all three the same bridge, and the maintenance engineer there sent us the deck temperature log without being asked twice. Two are a failing gearbox in a grain elevator, recorded five weeks apart, the second one four days before the gearbox was replaced. One is a ventilation stack we can locate but not get inside. ## Nobody in this story lied This is the part the desk wants to be careful about. Nerea Ibarrola-Dunn in Zaragoza sent us upload 611. Upload 611 is the file, seventh generation. She never claimed to have recorded it; her neighbour had sent it to her, and she sent it on, and our first letter to her wrongly implied she was the source. That was our error and it is corrected here. That is the shape of nearly all of it. People passed on what somebody had passed to them. There is no operation, no seeding campaign, and no evidence anyone set out to deceive. We cannot identify the first uploader and we are not going to guess at one. ## What this desk takes from it The sound is real in nine places and it is a hoist brake, a flare stack, a bridge deck warming up, and a gearbox four days from failure. Everywhere else it is one file with a licence number. But the recordist's reply, printed below, contains the observation this desk could not get around and could not verify either. He says that forty-three seconds of a mine brake, played to people in thirty-one countries with no context at all, sounds to almost all of them like the sky. He is right that it does. We have no way to test why. ## Sources (invented) - Dr. Yusra Lindqvist-Achike, Audio forensics, Delft — Given the corpus with filenames and metadata stripped; ran the correlation independently, and her code is published (February–June 2026) - Ansel Kirchmayr-Bello, Field recordist; made the original cue in 2009 — Interviewed by video call for two hours; supplied his session notes and the unedited 19-minute master (June 2026) - Bohdan Ferreira-Szabo, Winding-engine engineer, Upper Silesia — Interviewed at the shaft head; played four of our unidentified recordings without being told what they were (June 2026) - Callum Nakashima-Prieto, Bridge maintenance engineer, Ontario — Interviewed by telephone; supplied the deck temperature log for the night of one recording (July 2026) - Nerea Ibarrola-Dunn, Reader, Zaragoza; sent us upload 611 — Interviewed by video call; showed us the message her neighbour had sent her and the one she forwarded (May 2026) ## What we could not confirm - Who first uploaded it. The earliest copy we can date is from October 2013 and is already second-generation. The account that posted it closed in 2016, and the platform will not confirm to us that the account existed. - Whether the 133 originals are 133 events. Some are certainly the same event recorded by two people standing apart; we could pair only four with confidence, using aircraft passing overhead. - Whether industrial noise explains the other 124. It explains nine. The remaining recordings are real, are unexplained, and this newspaper is not going to write the word 'probably' in front of a machine it did not find. ## Right of reply **Ansel Kirchmayr-Bello, field recordist** (Replied on 19 June. Printed in full and unedited.): > I want to start by saying that I am glad someone finally rang me, and then I want to disagree with almost everything about how you have framed this. > > You keep calling it 'the file'. It is not a file. It is a recording of a machine. > > On the fourteenth of November 2009 I stood two hundred metres from a winding tower in Upper Silesia in the rain for five hours because I had a commission for industrial atmospheres and I needed a brake. At about ten past three in the morning the cage came up and the brake did what it does, and I got nineteen minutes of it, and forty-three seconds of that are as good as anything I have recorded in thirty years. I edited it, I named it, I delivered it, the library catalogued it as 4413-07, and it has been on sale ever since to anybody with sixty euros. > > So when your newspaper writes that a thousand people were fooled by a sound effect, please be precise about what you mean. They were not listening to a synthesiser. They were listening to Poland. > > Now, my objection. You have written a story in which I am the contaminant. The clean data is the 133, and my work is the noise you had to subtract to get to it. I understand why the arithmetic goes that way and I still think it is the wrong way round, because the interesting fact is not that the copy spread. Copies always spread. The interesting fact is that a recording of a brake on a mine hoist, played to people in thirty-one countries with no context, sounds to almost all of them like the sky. > > That is not credulity. That is a real property of that sound and I have known it since the night I recorded it, because the four men who came off shift at half past three heard it every working day of their lives and two of them stopped and looked up. > > One more thing and then I am finished. You will publish that I have had messages about this since 2020. I have. Some of them are angry, from people who feel they were made a fool of, and I have answered every one of those, because they were not made a fool of by me. But most of them are not angry. Most of them are people describing where they were standing when they first heard it and what they thought was happening, and several of them are the best writing about sound I have ever been sent. > > I would ask you to print that the licence is still available, the catalogue number is still 4413-07, and the credit requirement your reporters used to unpick all this is the same clause that people complain about when they have to type it into a video description. It is there so that work can be traced back to the person who did it. It worked. You are talking to me. --- They Buried is a satirical newspaper. Every story, source, document and person in it is invented. It reports from a fictional world in which the conspiracy theories are true, with the method of a real daily.