About Sound Decibel Meter

Sound Decibel Meter is a free, browser‑based sound‑level meter built to make professional‑grade noise measurement universally accessible. No account, no install, no advertising, no audio leaving your device. The core meter, the reference content, and every page on this site are designed for one purpose: to help you measure the noise in your life accurately, understand what the numbers mean, and act on them.

This page covers what the project is, why it exists, how it differs from similar tools, and how we approach privacy and data handling. If you want to know what the meter can do or how to use it, the user guide is the right starting point.

Mission

Hearing loss is one of the most common preventable health conditions in the world. The World Health Organization estimates that over 1.5 billion people live with some degree of hearing loss, with about a third of cases attributable to noise exposure that could have been avoided with awareness, measurement, and appropriate protection.

The instruments that measure noise — Class 1 and Class 2 sound‑level meters certified to IEC 61672‑1 — are professional tools. They cost hundreds to thousands of dollars, require calibration discipline, and sit firmly outside the budget and patience of most people who would benefit from one.

Modern smartphones have all the hardware needed to do useful sound measurement: a microphone, an ADC, enough compute to apply A‑weighting and FFT analysis in real time. What's been missing is a well‑designed, multilingual, free browser interface that turns that hardware into a meter without asking the user to install anything, create an account, or accept tracking.

That gap is what this project fills.

How we got here

The decibel‑meter web app market is small but real — a handful of sites compete for the same set of search queries. The leading competitor in English is decibelmeter.org, an excellent product built by a small independent team using a similar technical stack. Its existence proves the demand. What it doesn't do is serve the non‑English‑speaking majority of the world: the WHO estimates that nearly half of all people living with noise‑induced hearing loss are in Asia, where the dominant search languages are Chinese, Hindi, Indonesian, and Vietnamese — none of which the existing tools fully serve.

We started this project to close that gap. The meter itself is a re‑implementation in modern Next.js with React 19, optimized for mobile and desktop equally, with all the analysis on‑device. The content matrix is parallel: English first, then a planned 30‑language expansion with original (not machine‑translated) content for each target market.

What we do differently

Tools in this space tend to converge on the same feature set, so it's worth being explicit about the differences:

Multilingual depth

We treat translation as a content problem, not a localization problem. The technical documentation on the science page, health page, and workplace page is rewritten in each target language by a native speaker familiar with the domain — not run through a machine translator and lightly edited. The reference comparison chart is adapted to local references where appropriate (a "subway train" reference is more useful in Tokyo than in rural Wyoming).

Community noise framing

US‑based competitors lean heavily on OSHA and the 85 dBA / 90 dBA occupational framing because that's the regulatory framework most of their audience operates under. For readers outside the US, the more relevant framework is the WHO Environmental Noise Guidelines (community noise) and the EU Directive 2003/10/EC (occupational, with a stricter 85 dBA action value and 87 dBA exposure limit enforced at the ear).

We cite all three frameworks throughout, and let readers see the actual numerical differences rather than defaulting to whichever standard is most familiar to the page author.

Browser‑first, install‑optional

The full functionality of the meter — calibration, weighting, spectrum analysis, reference matching, statistics — is in the browser, not in a paid app. There is no premium tier. There is no "upgrade for advanced features" button. The site is supported by modest affiliate links to third‑party hearing protection on pages where they're contextually relevant (health, use cases) — disclosed clearly on each page where they appear. We do not run display ads, and we do not have an audio analytics product.

Honest limits

Browser meters are not laboratory instruments, and we don't pretend otherwise. The calibration page, the FAQ, and the tips page all explicitly cover where a phone meter is and isn't reliable: the clipping ceiling around 95 – 110 dBA, the non‑flat frequency response of consumer microphones, the fact that it's not a Class 2 instrument and shouldn't be used as one. Knowing the limits is what makes the readings trustworthy within them.

Privacy

Privacy is structural, not promised:

• All audio processing happens in your browser. Microphone audio is routed through the Web Audio API to a JavaScript analyzer in the page. No audio samples, FFT frames, derived levels, or any other audio‑adjacent data are ever sent to a server. This is a property of how the page is built, not a policy we promise to follow — open the network tab during a measurement and you can verify it yourself.
• No account required. No email, no password, no profile. The meter works the same for everyone.
• Local persistence only. Your calibration offset, language preference, and theme are stored in your browser's local storage for the site origin. Clearing site data clears them.
• No third‑party trackers in the meter session. We use minimal privacy‑respecting analytics (page views, geographic country at the city level, no fingerprinting) on content pages, and none on the meter page during a measurement session.

Full details are in the privacy policy.

Standards we follow

The meter implements behavior consistent with the relevant international standards:

• A, C, and Z weighting per IEC 61672‑1 — the international standard for sound‑level meter performance.
• Time weighting (Fast 125 ms, Slow 1 s, Impulse 35/1500 ms) per IEC 61672‑1.
• Reference values in the comparison chart and use‑case pages drawn from NIOSH, CDC, WHO, EPA, and ISO 1996‑1/2.
• Hearing protection ratings per ANSI S3.19 (NRR) where mentioned.

The meter is not Class 1 or Class 2 certified — that designation requires hardware that consumer phones and laptops do not have, and formal traceable calibration that a browser cannot perform. It does, however, follow the same signal‑processing chain that a Class 2 meter follows, so its behavior is qualitatively comparable.

Differentiation roadmap

A few capabilities we're actively building toward:

• Data export — CSV and PDF logs with timestamps, useful for formal documentation of long‑term exposure (noise‑complaint cases, rental disputes, cumulative occupational exposure).
• Per‑device calibration profiles — named offsets for users who measure on multiple devices.
• Leq integration — the energy‑equivalent continuous level over arbitrary windows, currently approximated by Avg.
• Native PWA install — offline meter, home‑screen icon, no browser‑cache dependency.
• 30+ language content — beginning with the major Asian and Romance languages, expanding to cover the bulk of global search intent for sound‑measurement queries.

If any of these matters to you specifically, we'd like to hear about it. See contact below.

Contact

The fastest way to reach us is by email at [email protected]. We answer:

• Bug reports (please include browser, device, OS version, and a reproduction).
• Feature requests (especially from people in compliance, healthcare, music production, and education — the use cases that drive the roadmap).
• Translation contributions and corrections (every page is open to feedback from native speakers).
• Press, partnerships, and content collaborations.

We don't currently have a public bug tracker; that's planned alongside open‑sourcing the codebase. Until then, email is the channel.

Legal

For the formal terms governing use of this site and the meter, see the privacy policy and the terms of service. The short version: the meter is provided as‑is, without warranty, intended for personal and informational use, and explicitly not as a substitute for a calibrated sound‑level meter where one is required by law or by professional practice.