Decibel X:dB Sound Level Meter

Decibel X:dB Sound Level Meter

Frequency Spectrum Analyzer

162K ratings
796 reviews
Free
In-App Purchases

Details

  • Released
  • Updated
  • November 5, 2011
  • September 15, 2026

Features

Decibel X:dB Sound Level Meter video #1 for iPhone
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Decibel X:dB Sound Level Meter screenshot #11 for iPhone
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About

This app transforms your device into a professional sound level meter, precisely measuring ambient noise pressure. It offers advanced features like frequency analysis, historical data management, and dosimeter functions, making it useful for various applications and entertainment.

Precise sound pressure level measurement
Frequency spectrum analysis (FFT, BAR graphs)
Historical data recording and export
Dosimeter with NIOSH, OSHA standards
Apple Watch and Health App integration
Customizable calibration and filters
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What users say

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+2

What's New in Decibel X

9.9.7

September 15, 2026

Thanks for using Decibel X! Here's what's new for the version 9.9.7: ∿ [Fixes] - Camera: the dB readings and the graphs on the overlay now update smoothly along with the live video, instead of looking frozen Previously in version 9.9.6: ∿ [New] - Siri & Shortcuts: run the app hands-free - start or stop measuring, save a recording, run the dosimeter, take a photo or record a video, create a PDF report, share a recording, change the weighting, set a noise alert and more ∿ [New] - Ask Siri what a term means ("What does TWA mean in Decibel X?") without opening the app ∿ [New] - Search your recordings in the Data tab - by name, note, location or date - or just ask Siri to find them ∿ [New] - Filter recordings by date: Today, last 7 or 30 days, or a custom range ∿ [New] - Swipe a recording to delete it, or drag one straight into Mail, Files or Notes ∿ [New] - Photos, videos and recordings now log the full street address instead of only the city ∿ [New] - The loud noise alert now shows its threshold value right on the meter ∿ [Improvements] - PDF reports are built faster and reused when nothing has changed ∿ [Improvements] - Reports for the running session now include the audio recording ∿ [Improvements] - "Running in background" is now off by default on new installs ∿ [Improvements] - Refreshed look on iOS 26 and iOS 27, and support for the newest devices ∿ [Fixes] - Fix crashes when starting a measurement with Siri, and when leaving the app ∿ [Fixes] - Fix recordings saved through Siri or Shortcuts coming out without audio ∿ [Fixes] - Fix "Stop measuring" telling you it had already stopped while it was still running ∿ [Fixes] - Fix the meter showing a wrong duration, and Reset not clearing it ∿ [Fixes] - Fix deleting several recordings at once leaving their files behind ∿ [Fixes] - Several other minor tweaks & bug fixes What to expect in upcoming versions: ∿ Support external or bluetooth mics ∿ Hearing test

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Subscription plans

Monthly Membership

Get everything Decibel X has to offer

$5.991 Month
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2

In-App Purchases

$2.99

Data Export

No limits when saving data

User reviews

Comprei e adicionaram propaganda

E bom, mas adicionaram propaganda depois da cultura de assinatura. Não vou assinar nada. Eu COMPREI o app. Não podem me obrigar a ficar vendo propaganda.

Response from developer

Hi, Fabinfranco! We're sorry if the current payment method didn't meet your expectations. Once you purchase the app, ads will be completely removed. To help us assist you better, please provide more details about the issue you are experiencing. Thank you!

Good app

Would have given it a 5 , but it lacks a user’s manual.

Requires $50 in app purchase before it opens

As soon as you open the app it wants $50 payment to proceed past the first screen

Protection

Nice to know when sound is dangerously loud! Thanks…

Useful for measuring in-home volume

Great

Developer apps

User experience

🐞

Reported Bugs

3 issues

App crashes when deleting recordings

Bug

Microphone issues on certain devices

Bug

Saved files not accessible after updates

Bug

Requested Features

5 requests

Add GPS coordinates to recordings

Feature

Improve reporting and data export

Feature

Provide more weighting options

Feature

Extend frequency range

Feature

Allow music playback while using the app

Feature

FAQ

What does Decibel X do?

Decibel X turns your iOS device into a professional sound level meter. It precisely measures the sound pressure level (SPL) around you and offers advanced features like frequency spectrum analysis and historical data management.

What are the key features of Decibel X?

Key features include trusted accuracy with pre-calibrated measurements, Apple Watch support, Health App integration, various frequency weighting filters (A, C, Z, ITU-R 468), powerful history data management with export options, dosimeter functions, and real-time FFT and BAR graphs for frequency analysis.

Is Decibel X free to use?

The app is free to download and use, but it offers in-app purchases for additional features and functionalities. This allows users to access core features for free while enabling advanced options for those who need them.

What devices is Decibel X compatible with?

Decibel X is designed for iOS devices and is tested and pre-calibrated for all Apple devices. It also supports Apple Watch for convenient on-wrist monitoring and can integrate with the Health App.

What are some common use cases for Decibel X?

Common use cases include measuring the noise level in your room, assessing the loudness of concerts or sporting events, conducting acoustic analysis, monitoring noise exposure for health and safety compliance (using dosimeter features), and for musical tests and frequency analysis.