An authority needs facts, not feelings. But "facts" here does not mean a professional measurement — it means a systematic, dated and honestly labelled set of observations. Anyone can build that, and it costs only time.
1. The noise log
The most valuable and simplest tool. One table, filled in regularly, is stronger than any single recording.
| What to record | Why |
|---|---|
| Date and exact time | Allows later comparison with the plant's operating schedule |
| Duration | Shows whether it is continuous or episodic |
| Wind direction and strength | The single biggest factor for low frequencies |
| Where you are (room, floor) | Shows how the noise moves through the building |
| Window open or shut | Separates the outdoor and indoor situation |
| Disturbance rating 1–10 | Lets a trend over time become visible |
| Consequence | "Could not sleep until 2:00" is more concrete than "it disturbed me" |
Three months of regular entries is serious material. Three scattered notes across a year is not.
2. Audio recordings
A phone recording is not a measurement, but it is useful evidence of the noise's character — that it is monotonous, continuous and tonal.
- Record at least 60 seconds. Short clips do not convey monotony.
- Film video with a visible clock, or open the recording by stating the date and time aloud.
- Record from the same spot every time, so the recordings are comparable with each other.
- If you can, also record a moment when the noise is absent. The contrast is more convincing than the noise itself.
- Turn off noise suppression and "voice mode" — they cut precisely the low frequencies.
An important note on recordings
Phone microphones reproduce low frequencies poorly. A recording can sound far weaker than the reality. That is no reason not to make one — but it is a reason to attach a note saying that what is audible does not reflect actual perception in the room.
3. Phone decibel apps
These are useful on one condition: that you label them honestly.
The app is not calibrated, the phone's microphone is designed for speech, and the result can be off by 5–15 decibels. On top of that, most phones measure almost nothing below 100 Hz.
| Don't write | Do write |
|---|---|
| "I measured 78 dB" | "Indicative, non-accredited, phone app, outdoors at the window — around 70–78 dB(A)" |
The first formulation lets an authority dismiss your entire submission in one sentence. The second turns it into supporting information that cannot be knocked down, because you have already stated its limits yourself.
4. Neighbours' accounts
One household is a complaint. Ten households are a situation.
You do not need signatures on a formal document. It is enough for each person to write a short description in their own words — how long they have lived there, what they hear, how it affects them. Many separate accounts are more persuasive than one collective text.
5. What ruins evidence
The mistakes that most often make material worthless:
- Exaggeration. One unverifiable figure casts doubt on everything else.
- Emotion without data. "It is unbearable" cannot be recorded; "from 23:40 to 02:10, wind from the north-west" can.
- Accusations. Claims about a company's intentions or unlawful conduct shift the subject from the noise to your assertions.
- Hiding what doesn't suit you. If the noise is inaudible during the day, say so. It substantially strengthens the claim about nights.
What to do with it
Organise the material into one file in chronological order and attach it to your submission as an annex rather than pasting it into the text. The submission should stay short and readable; the evidence should be there for whoever wants to look.
What this site documents
This article is published by the Jūrkalnes and Irlavas neighbourhood community. We document the industrial noise produced by the outdoor Nestro filter at SIA Livonia Print, Jūrkalnes iela 15/25, Riga. The installation has run 24 hours a day since 2021, and its hum reaches around 12 streets. The residents’ request to the company is a single one: fit an acoustic enclosure around the filter and sound insulation on the air ducts.
