Decibel Shield: the decibel meter app your iPhone deserves

Decibel Shield - dB Meter is a free decibel meter app for iPhone and iPad: measure sound level and get real-time alerts before noise becomes unsafe. It logs every measurement with history and trends, syncs with Apple Health and iCloud, and keeps measuring in the background. It holds a 4.7-star average across 604 App Store ratings.

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Download on the App Store Free, with an optional Premium upgrade.

4.7★ average · 604 ratings · iOS 15.6+ · by APPSTACK LLC (ratings as of 2026-09-06)

Decibel Shield Measure screen reading 48 dB, marked Safe, with a 45 dB average and 48 dB maximum, and Reset, Stop and Save buttonsDecibel Shield Measure screen reading 92 dB, marked Danger, showing the 85 dB threshold exceeded once with the time it happenedDecibel Shield History screen listing saved readings named Live Concert, Outdoor Cafe and Baby Room with date, current, maximum and average dB, location, and a Danger, Caution or Safe labelDecibel Shield Audio screen with the white noise generator: noise colour picker, timer from 10 minutes to unlimited, Play and Stop
The four screens from the App Store listing: live meter, threshold alert, saved readings, white noise generator (version 6.8.3).

What you get beyond the web meter

The free online meter on this site is a quick estimate. The iOS app is the instrument: it stays running in the background, keeps your history, charts your exposure trends, and writes to Apple Health.

Decibel Shield features
Feature What it does
Real-time decibel monitoring Live dB readout with a dynamic VU meter view and dominant-frequency detection.
Exposure alerts Get notified the moment noise crosses your set threshold, with age-adjusted safety levels.
Measurement history Every session logged with date and time stamps, synced across devices with iCloud, exportable as CSV.
Apple Health integration Save sound levels to the Health app alongside your other hearing data (Premium).
Trends Insight into your sound exposure over the last week, month, quarter, and year.
Sound classification The app identifies what it hears — speech, music, and more.
Location tagging Remember where each measurement was taken.
Background measuring Keep measuring while the app is in the background.
Calibration Built-in device corrections, plus a fine-tuning slider to match a reference meter (Premium).
Noise & nature sounds White, brown and pink noise plus fan, ocean, rainfall, water and forest sounds for masking and sleep.

App facts

Decibel Shield is a noise meter app in the App Store's Utilities category. Every fact below comes from the public App Store listing:

Decibel Shield App Store facts (public listing, as of 2026-09-06)
Price Free download; Premium $44.99 per year
Rating 4.7★ across 604 App Store ratings
Current version 6.8.3 (44.4 MB)
Requires iOS 15.6 or later, on iPhone and iPad
Also runs on Mac (macOS 12.5 or later with Apple M1 chip or later) and Apple Vision (visionOS 1.0 or later)
App Store category Utilities
Age rating 4+
Developer APPSTACK LLC

Honest answers

Is Decibel Shield a good sound meter app?

We're biased — it's ours — so here are the verifiable facts: 4.7 stars across hundreds of App Store ratings, real-time readings with history and trends, Apple Health sync, no ads, free to start. For occupational or compliance measurements, use NIOSH's validated meter app; for everyday exposure tracking, that's exactly what Decibel Shield is built for.

How much does Decibel Shield cost?

The app is free to download and measure with. Premium — which unlocks Apple Health sync, calibration fine-tuning, auto-save and more — is $44.99 per year after a 7-day free trial.

Does it show ads?

No. There are no ad networks in the app — no banners, no interstitials. The free tier is supported by the optional Premium subscription, nothing else.

Does it work offline?

Yes — sound measurement runs entirely on the device, so the meter works without an internet connection. iCloud sync of your saved readings happens when you are back online.

What data does the app collect?

Per the App Store privacy label, the app collects usage data and product-interaction analytics that are not linked to your identity. Audio is processed on-device for measurement.

What iOS version do I need?

Decibel Shield requires iOS 15.6 or later and supports iPhone and iPad.

Want to know how accurate phone meters can get before you download? Start with can your iPhone measure decibels accurately?