Noise pollution caused by church towers in Ljubljana

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One Sunday I woke up to incessant and very loud tolling of nearby church bell. It was 9 o’clock in the morning. It didn’t seem fair that an institution can cause so much noise so early. As I work hard during the week, run almost every day, and write software, sometimes until late, I would very much prefer to sleep. The clergy would probably say that honest Christians are already awake at that time, so I’m no good anyway.

I then decided to research the matter. A number of facts surfaced, the most startling of which is a state decree, which states that church bells are not categorized as noise. If an inspector came to my house, measured sound levels while this was going on, and found out that they exceed proscribed levels, he would not be able to fine the aforementioned institution. He would probably bill me for the expenses of his time. But I digress.

Action was taken: city geometry was imported into computer along with church bell coordinates. Aggregate sound pressure for each building was calculated, then ranged so it could be visualized. Additionally, a point where there is least such noise was calculated. You can see results below. The point with least noise is on the green marker in the lower left corner. Lucky owner of that house.

Note: please notify me before embedding this map in your page.

I have to admit that the calculation is naive. It doesn’t take into account the elevation model, neither it accounts for building heights. Sound reflection is also ignored. But my curiosity was satisfied. I do live in the red zone.

Here are same maps on different scales. One is for entire country of Slovenia.

Edit: after this post went viral and other media ( published their own versions linking to me, I feel compelled to clarify my position about church bells. Personally, that is, as a person, and not a member of any organization, I’m bothered by long intervals of loud tolling on Sunday mornings. I’m told by other people they don’t like that either, and some other people point out that any attempt at playing music at this volume at similar hour of day would not end well.

I do somewhat like single chimes announcing hours of day, even at night. It’s a part of urban environment, and I’d probably subconsciously miss it should they quit. I’m not against Catholicism, the Church, or faith of any denomination.

When you toll so loudly next time please consider:

  • do unto others as you would have them do to you,
  • would Christ approve of that?



  1. Marko

    Please include the church at 46.094101,14.511794 (Sv. Kancijan / Ježica) in your research. This church here loud, it tirelessly rings every single morning (without exception) at 7am for from 5 to 15 minutes with three out of tune bells (melodically and rhythmically). It never rings less than 5 minutes! If it rings for “only” 5 minutes it will ring again for another 5 to 10 in just 10 minutes. You should never keep close on a church holiday. There were already complaints issued, inspectors measured the loudness etc, but the result it seems was louder and even longer ringing done in spite ( This church was in the papers more than a few times due to loud and annoying church bells.

  2. Miha

    This seems to be an interesting work, but I am wondering how did you “aggregate [the] sound pressure for each building”, actually how did you calculate that? I am really wondering, where did you get the information about the sound pressure of the individual church? In addition, how did you include the reflections, resonance and other sound reinforcement or absorption phenomena that may occur due to the surrounding area?

    Keep up with the good work!

  3. Bob Burgher

    Very nicely done, but I’m afraid that there’s one important parameter that you’ve failed to include: the ugliness of the sound.
    Where I come from bells are tuned, so that the resulting sound is at least pleasant to hear – especially when change ringing. But it seems that in Slovenia bells are made by smelting a load of scrap (crap?) iron and moulding it into a bell-like shape, with no concern for it’s musical characteristics. The resultant cacophony made by a priest representing that first century raconteur and part-time magician, Jesus H Christ, in any village bell tower at seven in the morning (nine you say? lucky you), sounds more as though it emanates from the depths of Mordor, rather than the rural idyll one would expect from the scenery glimpsed the evening before.
    I’ve often considered that if were to win the lottery – highly unlikely due to the fact that I never buy a ticket – I would see how many Slovenian bell towers I could fill with cavity wall insulation before being kicked out of the country.

  4. Irena

    Some legislation explanation from Slovenian police:
    V skladu z Direktivo 2002/49 ES je hrup opredeljen kot nezaželen ali škodljiv zunanji zvok, ki ga povzročajo človekove aktivnosti, vključno s hrupom, ki ga oddajajo prevozna sredstva v javnem prometu, industrijske naprave itd.

    Zvok, ki nastaja zaradi zvonjenja cerkvenih zvonov, je podoben zvoku drugih glasbil in običajno za ljudi ni nezaželen ali moteč. V skladu z zakonodajo Evropske unije cerkveni zvonovi ne povzročajo hrupa, zato v trenutno veljavni zakonodaji na področju varstva okolja, preneseni v slovenski pravni red, njihovo zvonjenje ne predstavlja kršitve.

    Cerkvene zvonove sicer omenja 2. člen Pravilnika o prvih meritvah in obratovalnem monitoringu hrupa za vire hrupa ter o pogojih za njegovo izvajanje (Uradni list RS, številka 70/06), vendar ta določba nima pravne podlage v Uredbi o mejnih vrednostih kazalcev hrupa v okolju, ki v 3. členu opredeljuje vire onesnaževanja okolja s hrupom.

    Predlagamo vam, da poskušate zadevo sporazumno reševati s pristojnimi institucijami oziroma za razrešitev opisanega problema uporabite civilnopravne poti.

    Another interesting source of potential information is this graduate thesis:

    Different suggestions and opinions on what the government should do about it (and what noise level does it reach):

    Again, I stress that a carefully organized pastafarian event could potentially do a lot of good.

  5. Irena

    May I point out that the bells of a very active church in Tabor, Ljubljana, seem to be missing. I can assure you they had dramatic effects on my sleep. I do not know where you have taken the geospatial data of church bells from, but would like to know what value of the noise did you enter for your calculations? How did you define noise and did you perhaps do any measurements to confirm the bells did reach the level of noise? Some gradient should be taken into account. All red (dark red or red) doesnt help much, if we do not have any reference, what are the values. If the law is like you say, does this apply to any religious community (muslim and pastafarian alike?). If not, that would be the breech of human rights. I propose forming a loud pastafarian event. Every Friday from 10.00 pm – 2.00 (minimum time for pastafarian prayer and recreation of pastafarian heaven, including a beer vulcano).

    • virostatiq

      Really? This seems to be the same church that gives me trouble. If so, it’s definitely on the map. Geospatial data comes from a open-source database.
      I looked around, but measurements of exact sound levels in dB doesn’t seem to exist for many churches in Slovenia, so I just treated them all the same. I’d very much like to incorporate this data if I could get it.
      Sound pressure is calculated according to formula on Wikipedia. It has a quadratic falloff.
      There is some gradient, it goes from red (max) to black (min). I tried HSB model, but then I thought a simple RGB gradient is more appropriate.
      Due to the fact that too many factors are not accessible, so the calculation is necessarily lacking, I settled to what I thought was good enough for casual viewing.

      • Irena

        Perhaps there is a misunderstanding of your color scheme. If bright red is the actual source of noise (church Tabor), then the darker areas are less noisy. As said, without a legend explaining what color means what, it is very difficult to interpret your map. Also, it would be useful to know what starting sound pressure did you use (at the very bell, for instance)? So this different sound pressure areas should be visible on the map legend (color scheme). If I understand correctly now, black is the least burdened area (and before, I assumed the opposite). Note that there is a definition in dB what level we perceive as noise and what level could actually cause ear drum damage.
        The problem with Tabor church is multifaceted: the church seems to enjoy using the bell, there is an active religious center, but also a relatively open space (due to a nearby park and somewhat frightened trees in it), which allows the sound to propagate in an undisturbed way – directly to exposed buildings. The bell tower is not very high, either (not sure if this would help, though).

        Try borrowing an actual sound pressure measurement tool for a perfection of this experiment. I would help you, but I am no longer in the neighbourhood. You do have my deepest empathy, though. I can of course also tell you which earplugs work best.
        I am personally able to sleep with these both while children are screaming on a plane and in my bed – a neighbour of an active construction work starting at 7.00 am. The good part is they are very soft and easy to insert. The down side is they dont work well anymore after a couple of days, so you need a replacement (they come in a package of 10). But I guess thats hygienic anyway. They are always within my hand reach.

        • Kneejo

          Please don’t wear earplugs every night. I did that for a while and got a nasty infection in my ear canal, that if left untreated would have gone to my brain. Tell that church that when they tell you to wear earplugs.

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