About Noisecatcher
A tool for social and sonic justice, public health, research, journalism, and art.
What this is
Noisecatcher is a free, open web application that gives anyone with a smartphone the ability to measure noise pollution in real time, understand its health consequences, and contribute to a living global map of acoustic environments.
It is part of the Politics of Noise project — an ongoing artistic, academic, and civic research practice conducted by Sylvain Souklaye. Its goal is to democratize the kind of acoustic monitoring work that has historically been restricted to institutions, and to create the infrastructure for communities to document, contest, and act on noise as an environmental and social justice issue.
The app covers 14 noise source categories — traffic, emergency, municipal, construction, industrial, entertainment, neighbourhood, recreational vehicles, natural events, conflict zones, police brutality, harassment & gender-based / LGBTQ+ violence, political violence, and phone noise pollution — with 90+ specific subcategories for precise documentation. The Abécédaire now contains 107 entries spanning acoustics, health, law, environment, and critical theory, including sonic warfare, acoustic racism, psychoacoustic annoyance, machine listening, federated noise sensing, and political violence acoustics.
New in this version: a real-time spectrogram and statistical metrics (Leq, L10, L50, L90) during measurement sessions; audio file import and analysis with waveform, spectrogram, acoustic statistics, and YAMNet ML sound classification (521 AudioSet classes); live psychoacoustic metrics (Loudness, Sharpness, Roughness, Psychoacoustic Annoyance — Zwicker model); timestamp markers during recording; temporal pin status (predicted / active / historical); and Noise-Planet community data federation — overlay crowdsourced measurements on the map and export pins as NoiseCapture-compatible GeoJSON.
Social & sonic justice · Research · Journalism · Art
Noisecatcher is a tool for social and sonic justice — the position that acoustic environments are shaped by power, and that the right to a liveable soundscape is a political right unevenly distributed along the axes of class, race, gender, and geography. Measuring noise is not neutral. It is an act of naming what the powerful prefer to leave unnamed.
It is a tool for public health documentation: GPS-timestamped Leq measurements, L10/L50/L90 percentile statistics, EU noise dose, psychoacoustic annoyance scores, and printable PDF reports that can support formal complaints, medical records, and epidemiological research.
It is a tool for journalism: structured noise reports with statistical metadata, voice notes, GPS coordinates, and categorical tagging constitute raw material for investigative documentation of industrial facilities, transport infrastructure, construction projects, police operations, or public space harassment.
It is a tool for academic research: open data export in GeoJSON (NoiseCapture-compatible), statistical session outputs, and the Field Notebooks system for building longitudinal, categorised evidence corpora over time.
It is a tool for art and sonic practice: the spectrogram, psychoacoustic metrics, voice notes, and deep-listening methodology situate Noisecatcher inside a tradition of soundscape art, acoustic ecology, and counter-forensic practice — from R. Murray Schafer to Forensic Architecture. Attending fully to what an acoustic environment contains is both a discipline and an aesthetic act.
The Harassment & gender-based / LGBTQ+ violence category was built so that women, LGBTQ+ people, and all targets of targeted harassment can build a spatial and temporal record of where and when harassment occurs — translating lived experience into documented, mappable, dateable evidence. It includes dedicated subcategories for LGBTQ+ hate speech, targeted assault, and intimidation, alongside existing subcategories for street harassment, stalking, verbal assault, and domestic violence. Silence protects perpetrators. A pin, a voice note, and a timestamped reading do not.
On measurement and justice
The 2023 systematic review on sonic injustice and Brandon LaBelle's work on sonic agency both converge on a critical limit: measurement alone is not a justice practice. A noise map without community interpretation is just another dataset — one that can be absorbed by the same planning systems that produced the injustice in the first place.
Recording becomes a justice practice when three conditions are met: community control of the data, collective public interpretation of what the data means, and coordinated action that uses it to change policy or redistribute power. This is why Noisecatcher gives users full ownership of their recordings and pins (stored locally, never transmitted without consent), why the Act page provides documentation frameworks rather than just measurement thresholds, and why the Abécédaire names the political concepts — sonic injustice, aural counterpublics, acoustic counter-mapping — that give measurement its adversarial meaning.
Sources: Gieysztor et al., 'Sonic Injustice: A Systematic Review' (2023); LaBelle, B., Sonic Agency: Sound and Emergent Forms of Resistance (Goldsmiths Press, 2018).
Police brutality & sonic warfare
Sound is not only a pollutant — it is a weapon. Police and security forces routinely deploy acoustic devices against protesters, journalists, and bystanders: LRADs (Long Range Acoustic Devices, maximum specification 162 dB SPL at source — LRAD 2000X manufacturer spec), flash-bang grenades, rubber bullet launchers, water cannons, and sustained low-altitude helicopter operations. Each causes documented permanent hearing damage, vestibular injury, and psychological trauma. Juliette Volcler's Extremely Loud (The New Press, 2013) documents the global deployment of these technologies — and names the political logic that makes them possible: the "non-lethal" classification is a terminological sleight of hand that shifts accountability and enables harm without legal consequence. The ear has no eyelid. It cannot close.
Noisecatcher has a dedicated Police brutality category with subcategories for each weapon type, alongside the Conflict zone category for war and military contexts. The Abécédaire entries on Police Brutality & Acoustic Violence, Sonic Warfare, and LRAD document the legal frameworks, injury records, and global deployment history.
If you are at a protest or near police acoustic weapons: protect your hearing first — distance yourself, use ear protection if available. Record second. Your GPS-tagged, timestamped measurements are civic evidence that can support legal complaints, accountability investigations, and press documentation.
Why noise matters
Noise pollution kills. Chronic exposure to traffic, industrial, and aviation noise is linked to cardiovascular disease, stroke, hypertension, impaired cognitive development in children, sleep disruption, type 2 diabetes, and psychological trauma. In Europe alone — the second largest environmental health risk after air pollution — the European Environment Agency (2025) estimates 73,000 premature deaths per year, 1.3 million DALYs lost, 22,000 new type 2 diabetes cases, and €95.6 billion in economic costs, all from transport noise. These are European figures only: no equivalent global estimate exists.
Noise is also unequally distributed. It follows the geography of poverty, race, and dispossession. US federal highway programmes routed infrastructure through low-income and minority neighbourhoods at a 90% federal cost-share — institutionalising sonic inequity as structural racism (Haskell, 2022; Casey et al., EHP 2017). The same pattern appears across post-apartheid Cape Town (Watkins/UCT, 2020), postcolonial Mapuche territories (Cárcamo-Huechante, 2022), and cities from Cairo to São Paulo. Mapping noise is mapping power.
The Abécédaire
One of Noisecatcher's core commitments is linguistic: to build a shared vocabulary for noise pollution that is both scientifically grounded and politically legible. The Abécédaire is a living glossary — expanding over time with contributions from researchers, activists, and communities. Its aim is not only education but emancipation: to give people the words to name what is being done to them.
It covers the full spectrum: acoustic physics (infrasound, impulse noise, spectrogram, masking, psychoacoustic metrics — Loudness, Sharpness, Roughness, PA), health science (hearing loss, cardiovascular effects, cognitive development), legal frameworks (WHO guidelines, OSHA, environmental law), critical theory (acoustic racism, sonic warfare, police brutality, political violence acoustics, Attali's political economy of noise), civic methodology (participatory sensing, federated noise sensing, quiet areas, the right to the city), and now ecology — ecoacoustics, open acoustic sensing hardware, and the critique of training data bias in AI sound classifiers.
Ethos & practice
Noisecatcher is not merely a measurement tool. It is an electroacoustic instrument — a device that mediates between the acoustic world and collective knowledge — and a co-presence device: through its peer-to-peer layer, listeners who are physically dispersed become acoustically present to one another, sharing evidence without a central server. It is also a phenomenological instrument — a means of being present to sound, to place, and to one another. Its ethos is built on a core principle: the human body is the primary sensing device. The smartphone makes nothing perceptible that the ear has not already received. The human device is the necessary condition for the tech device to exist.
The smartphone's greatest technical advantage is not that it contains a microphone. It is that it combines a microphone with GPS, compass, accelerometer, and networking — making every recording simultaneously an audio file, a location, a direction, and a movement trace. Traditional field recording captures sounds. A smartphone captures relationships between sounds, places, people, and power. That is the genuinely new methodology that Noisecatcher is built on, and where the most promising directions for acoustic justice work are emerging.
The same recording made at the same moment can answer five distinct questions simultaneously: whether the noise level is harmful to human health (dB Leq); whether biological sound is being acoustically masked by industrial noise (NDSI — biophony vs. anthrophony ratio); which community bears the burden (GPS + category); whether the pattern is chronic or episodic (timestamp + repeat sessions); and what it means to the people who live there (voice note + description). No institution currently operates a community observatory that combines all five layers. That is what Noisecatcher is designed to grow into.
External microphone
An external microphone connected to your smartphone is fully supported — and often improves measurement accuracy. Lavalier, cardioid, and omnidirectional microphones plugged via the headphone jack or USB-C/Lightning adapter are detected automatically. When multiple audio input devices are available, a device selector appears above the Start button on the Meter screen, letting you choose which microphone to use.
Recommended for field recording, documentation at a distance from a sound source, or situations where the phone itself cannot be positioned optimally. See the Microphones guide →
Noise-canceling earphones are not allowed
Earbuds and earphones with active noise cancellation are explicitly incompatible with the ethos of Noisecatcher and must not be used during a measurement session.
Noise cancellation is a technological solution to a structural problem. It addresses noise at the individual, private level — at the cost of severing three fundamental connections:
- People from each other. A listener wearing noise-canceling headphones removes themselves from the acoustic commons. They hear less of what others hear. The shared sonic condition — the condition that generates solidarity — is dissolved.
- People from their environment. The soundscape carries information: about danger, about place, about inequality, about the presence of others. Canceling it cancels the evidence. What is not heard cannot be documented, contested, or remembered.
- The self from its own condition. The self is at the center of the listening experience. To cancel ambient sound is to remove the self from its own acoustic situation — to make oneself less present, not more. Deep listening begins with accepting what is there.
Noise-canceling technology is a profitable industry built on privatizing a response to a public health crisis. Noisecatcher does not participate in that privatization. Binaural headsets without active noise cancellation are acceptable for listening to recordings and practicing deep listening.
Deep listening as political act
The practice of listening without cancellation — of attending fully to what the acoustic environment contains — is both a phenomenological discipline and a political stance. It insists that the conditions of noise are real, shared, and worth documenting. It refuses the private escape of technological mitigation in favour of collective witnessing.
Noisecatcher recordings are acts of testimony. When you measure sound, you are naming a condition. When you pin a location, you are making an argument about space, power, and the right to a liveable acoustic environment. Listening here is social. Listening here is political.
Measurement methodology & known limitations
How dBA / dBC / dBZ are computed, NDSI ecological scoring, psychoacoustic metrics, forensic chain of custody, AI classification caveats, and all structural limitations documented honestly — on the Methodology page.
Inspiration & kindred work
Noise pollution research, advocacy, and community sensing exists on every continent. The resources below are organised by theme and geography.
Police brutality & documentation
Amnesty International — Crowd Control: A Deadly Business (2015) — global review of LRAD, rubber bullets, tear gasHuman Rights Watch — Kettling Protesters in the Bronx (2021) — acoustic and physical crowd control documentationUN Special Rapporteur — A/HRC/44/24 (2020) — acoustic weapons and protest rights under international lawDésarmons-les (France) — base de données des blessés par LBD 40, grenades, et armes de maintien de l'ordreObservatoire des pratiques policières (France) — documentation des violences sonores et physiquesForensic Architecture — The Use of Force in Protests (acoustic & chemical weapons, spatial audio analysis)ACLU — The Politics of Dissent: Policing Protest in America — sound cannons, LRAD, mass arrestsThe Intercept — Standing Rock investigation — LRAD, water cannon, acoustic harassment of water protectorsSonic warfare & acoustic weapons — theory
Steve Goodman — Sonic Warfare: Sound, Affect, and the Ecology of Fear (MIT Press, 2010)Juliette Volcler — Extremely Loud: Sound as a Weapon (The New Press, 2013)Suzanne Cusick — 'Music as Torture / Music as Weapon' (Transcultural Music Review, 2006)UN Special Rapporteur on Peaceful Assembly — reports on acoustic crowd control devicesAfrica
NESREA Nigeria — National Environmental Noise Standards & enforcementNEMA Kenya — Noise & Vibration Pollution Control Regulations (2009)EPA Ghana — community noise regulationDFFE South Africa — NEMA noise provisionsAsia & Pacific
中国生态环境部 — 噪声污染防治行动计划 2021–2025 (China MEE National Noise Action Plan)CPCB India — National Ambient Noise Monitoring Network, 35 cities국가소음정보시스템 — South Korea National Noise Information System環境省 — 騒音・振動 (Japan Ministry of Environment — Noise & Vibration)NEA Singapore — community and construction noise regulationLatin America
CONAMA Brasil — Resolução 001/90, pioneering national noise regulationMADS Colombia — Resolución 0627/2006, norma nacional de ruido ambientalIBAMA Brasil — poluição sonora e fiscalização ambientalMiddle East & North Africa
وزارة التغيير المناخي والبيئة — UAE noise standards & complaints (800900)وزارة البيئة والمياه — Saudi Arabia environmental noise regulationMinistère de la Transition Écologique — Maroc / Morocco noise frameworkOpen science & community sensing
Noise Planet (Université Gustave Eiffel) — open crowdsourced noise data, global WFS/WMS API — federated inside NoisecatcherNoiseCapture — open-source Android noise sensing app (GPL-3.0) — Noisecatcher exports NoiseCapture-compatible GeoJSONSensor.Community (formerly Luftdaten) — distributed citizen sensing network, open API and global mapEarshot NGO — acoustic advocacy networkWHO Environmental Noise Guidelines for the European Region (2018)European Environment Agency — Strategic Noise Maps, open datasets, noise in Europe reportsOpen-source technical ecosystem
MoSQITo (Eomys, LGPL-3.0) — open-source Python psychoacoustic metrics: Loudness, Sharpness, Roughness, Tonality — reference for Noisecatcher's JS implementationSQAT — Sound Quality Analysis Toolbox (Julia/Python, MIT) — independent Zwicker model reference implementation for cross-checkingAudioSet (Google Research) — 521-class ontology and 2M labelled audio clips — training data behind YAMNetONNX Runtime Web (Microsoft, MIT) — run any ONNX model in the browser — enables stronger classifiers (PANNs) as alternatives to YAMNetPANNs — Pretrained Audio Neural Networks (Kong et al., MIT) — stronger AudioSet tagging than YAMNet, exportable to ONNXDCASE — Detection and Classification of Acoustic Scenes and Events — annual challenge driving ML audio research, including domain generalisation across geographiesEssentia (MTG Barcelona, AGPL-3.0) — comprehensive C++/Python audio analysis library with 200+ algorithmsMeyda (MIT) — real-time audio feature extraction in JavaScript — RMS, spectral centroid, MFCC, chroma directly in the browserSpleeter (Deezer, MIT) — source separation library — potential for isolating noise sources in imported recordingsTurf.js (MIT) — modular geospatial analysis in JavaScript — spatial statistics, cluster detection, buffer zones on noise pinsH3 (Uber, Apache-2.0) — hexagonal hierarchical spatial indexing — noise density heatmaps at any resolutionPMTiles (Protomaps, BSD) — single-file cloud-optimised map tiles — enables offline-first map layers without a tile serverOpenStreetMap Nominatim (LGPL) — open reverse geocoding — auto-name pin locations from GPS coordinates for complaint lettersOverpass API (AGPL) — query OpenStreetMap features near a location — identify nearby schools, hospitals, parks to contextualise noise pinsDexie.js (Apache-2.0) — IndexedDB wrapper — robust offline pin storage so measurements persist without a serverWorkbox (Google, MIT) — service worker toolkit for offline-first PWA caching — full offline capability for the app shell and map tilesFreesound (Universitat Pompeu Fabra) — open, collaboratively built repository of audio samples and soundscapesForensic Architecture — methods & tools
Saydnaya (2016) — ear witnessing: acoustic reconstruction of a torture prison from blindfolded survivors' sound memories + impulse response modellingUse of Force in Protests — LRAD documentation, acoustic weapons analysis, multi-source video/audio synchronisation at protest sitesNuba Mountains (2014–2017) — aircraft sound identification, cross-referencing audio signatures with weapon typeTimemap (FA, DoNoHarm licence) — open-source temporal + spatial incident visualisation built on Leaflet + D3 — adaptable for noise event chronologiesmtriage (FA, MIT) — open-source media scraping + ML analysis pipeline: audio extraction, speech recognition, object detection — for large-scale acoustic evidence processingdatasheet-server (FA, MIT) — turn spreadsheet data into a queryable API — lightweight backend for noise documentation campaignsWeizman, E. — Forensic Architecture: Violence at the Threshold of Detectability (Zone Books, 2017) — theoretical framework for counter-forensicsBioacoustics & ecoacoustics
BirdNET (Cornell Lab + TU Chemnitz, MIT) — neural network identifying 6,000+ bird species from recordings — soundscape ecology use case for Noisecatcher's natural categoryOpenSoundscape (MIT, Carnegie Mellon Kitzes Lab) — Python toolkit for bioacoustic analysis, passive acoustic monitoring, acoustic index computationRainforest Connection (RFCx) — acoustic guardian technology: solar-powered sensors detecting chainsaw sound and illegal logging in real timeAudioMoth (Open Acoustic Devices, University of Southampton, MIT) — open-source acoustic sensor hardware: £50, battery-powered, deployable anywhere — fixed-installation citizen monitoringsoundecology (R, GPL-3.0) — compute acoustic indices (ACI, ADI, BIO, NDSI) from recordings — biodiversity proxies from passive monitoringOpen noise & audio datasets
NYC 311 Noise Complaints — 3M+ geolocated complaints since 2010 — geographic and temporal patterns across all boroughsBruitparif (Île-de-France) — open noise monitoring data for Paris region, continuous monitoring networkUrbanSound8K — 8,732 labelled urban sound clips, 10 classes (air conditioner, car horn, drilling, etc.) — training data reference, New York-biasedESC-50 — 2,000 clips, 50 environmental sound classes (Piczak, CC BY) — benchmark for environmental sound classifiers, European-biasedTAU Urban Acoustic Scenes (DCASE) — 10-second clips from 10 European cities, 10 scene classes — geographic domain shift benchmarkNoise-Planet OGC WFS endpoint — query crowdsourced dB(A) measurements by bounding box — live community dataEEA strategic noise map data — EU agglomerations, roads, railways, airports — official modelled noise contoursCritical theory & sound studies
Jacques Attali — Noise: The Political Economy of Music (1977/1985, Minnesota UP)Juliette Volcler — Le son comme arme / Extremely Loud: Sound as a Weapon (La Découverte 2011 / The New Press 2013)Juliette Volcler — Contrôle: comment s'inventa l'art de la manipulation sonore (La Découverte / Philharmonie de Paris, 2017)Juliette Volcler — L'orchestration du quotidien: design sonore et écoute au 21e siècle (La Découverte, 2022)Macs Smith — Paris and the Parasite: Noise, Health, and Politics in the Media City (MIT Press, 2021)Leonardo Cardoso — Sound-Politics in São Paulo (Oxford University Press, 2019)Goddard, Halligan & Hegarty (eds.) — Reverberations: The Philosophy, Aesthetics and Politics of Noise (Continuum, 2012)Stuart Sim — Manifesto for Silence: Confronting the Politics and Culture of Noise (Edinburgh UP, 2007)Rupert Cox — The Sound of the Sky Being Torn: A Political Ecology of Military Aircraft Noise (Bloomsbury, 2014)Salomé Voegelin — Listening to Noise and Silence: Towards a Philosophy of Sound Art (Continuum, 2010)Salomé Voegelin — The Political Possibility of Sound: Fragments of Listening (Bloomsbury, 2018)Jacob Kreutzfeldt — Acoustic Territoriality: City Planning and the Politics of Urban Sound (University of Copenhagen, 2007/2009)Lawrence Abu Hamdan — Earwitness Inventory (installation, 2018); Rubber Coated Steel (2016); Saydnaya: The Missing 19dB (2017)Nina Sun Eidsheim — The Race of Sound: Listening, Timbre, and Vocality (Duke, 2019)Julian Henriques — Sonic Bodies: Reggae Sound Systems (Continuum, 2011)Emily Thompson — The Soundscape of Modernity (MIT Press, 2002)Bull & Back (eds.) — The Auditory Culture Reader (Berg/Routledge, 2003)Monoskop — Noise (open wiki bibliography: Attali, Goodman, Voegelin, Schafer, Abu Hamdan, and the full noise studies canon)Syntone — revue critique de l'art radiophonique et de la création sonore (Beau Bruit / SCAM, 2008–)Steve Goodman — Sonic Warfare (MIT Press, 2010) — vibrational ontology, ecology of fear, audio virologyLuis E. Cárcamo-Huechante — Acoustic Colonialism: Acts of Mapuche Interference (Duke UP, 2022) — linguicide, colonial ear, allkütunWanda Canton — Sonic Rebellions: Sound and Social Justice (Routledge, 2024) — gentrification soundscapes, UK Drill, Algerian HirakShelley Trower — Senses of Vibration (Continuum/Bloomsbury, 2012) — railway shock, nervous illness, auditory unconsciousAndreas Weber — Enlivenment (MIT Press, 2019) — living commons, biopoetics; soundscape as shared alivenessJames Bridle — Ways of Being (FSG, 2022) — more-than-human democracy; noise silencing animal communication as political suppressionDavid George Haskell — Sounds Wild and Broken (Viking, 2022) — sensory extinction; sonic inequity as structural racismBernhard Siegert — Cultural Techniques (Fordham UP, 2015) — signal/noise as cultural filter; regulatory thresholds as political operationsJohn Cage — Silence (Wesleyan UP, 1961) — 4'33''; anechoic chamber; the city as indeterminate scoreBrandon LaBelle — Background Noise: Perspectives on Sound Art (Bloomsbury, 2nd ed. 2015) — noise as medium; acoustic space as relational and contestedO'Brien & Robin — On Minimalism: Documenting a Musical Movement (UC Press, 2023) — documentation as canon-making; who is included in the archiveNicholas de Monchaux — Local Code (Princeton Architectural Press, 2016) — urban acupuncture; GIS as justice tool; open data + local knowledgeField pamphlet
A printable guide to the ethos, key Abécédaire concepts, and practice of Noisecatcher. Save as PDF from your browser's print dialog. Fold into a booklet and carry it.
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Found something broken, inaccurate, or missing? Open an issue on GitHub — include your device, browser version, and steps to reproduce.
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Noisecatcher
by Sylvain Souklaye
Part of the Politics of Noise research practice. v0.5 — Meter · Spectrogram · Audio import · YAMNet · Psychoacoustics · Map · Earwitness pins · Voice notes · Field notebooks · WHO health dashboard · SHA-256 chain of custody · P2P community layer · Complaint letter generator · Noise-Planet federation · Transect export · Abécédaire · Act · PWA. 14 noise source categories · 107 Abécédaire entries · 16 languages.