# logSPL — Noise meter

> Advanced sound level meter with historical data and real-time histogram. (iPhone/iPad app by Fabien Lefebvre.)

- Source: https://appshunter.io/ios/app/logspl/id491999427 (this page in markdown: same URL + `.md`)
- Developer: [Fabien Lefebvre](https://appshunter.io/developer/338004167)
- Category: Utilities, Music
- Price: $1.99
- Rating: 5.00/5 from 1 App Store ratings · 7 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.2 · 1 MB
- Languages: American English, French (France)
- Released: 2012-01-07
- Data updated: 2026-09-06
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/logspl/id491999427/reviews.md

## What is logSPL?

This App is a full featured sound level meter, designed by a signal processing expert. It is iPhone/iPod/iPad compatible and adapts itself to the actual screen resolutions ("HD", "retina").

It consists in two parts: half top for basic features, half bottom for advanced ones (L95, %D, ...).

Half top was thus designed to be extremely easy to use. Only two settings are requested:
* select 'fast' or 'slow' update rate, which corresponds to 2 different integration periods
* select the type of weighting: A or C or Z (Z meaning roughly: no filtering)
These settings are saved when exiting the App.

Some tips for weighting:
* select A to evaluate the feeling of a person against a noise
* select Z to balance an audio system

Supports upside-down orientation.

The min and max values are monitored and displayed in green in the upper view. An average value (Leq, LAeq, ...) is computed on top of this: the green triangle. Take care that this latter corresponds to the logarithm of the average power and not to the average of logarithm values, which is completely different. Integration time for this average value is: all time since start-up of the App or last reset.
To reset these extreme and average values, touch the text named RESET.

Bottom view is used to display an historical curve. A grid is visible, with lines every 10dB vertical and 10s horizontal.

Half bottom now:
* a real-time histogram is displayed on left side
* it can compute L%: L95, L50, ...
* it can make some dosemetering: for this you need to set threshold, criterion and exchange values. This is for advanced users due to the complexity of underlying concepts

As for all sound-meter (at any price, hardware or software), you should calibrate it against a reference in order to achieve best accuracy. For this go to Mic. tab to add or remove a fixed offset to the measured values.

Any question ? Click on the Facebook icon !

## Key features

- Sound level measurement
- Adjustable update rates (fast/slow)
- Weighting options (A, C, Z)
- Min/max value monitoring
- Average value computation (Leq)
- Historical curve with grid
- Real-time histogram
- Dosemetering capabilities

## Recent user reviews (7 of 7)

All indexed reviews: https://appshunter.io/ios/app/logspl/id491999427/reviews.md

### 5/5 — Excellent Decibel Meter

*2014-10-15*

I am very impressed with the sensitivity and precision of this decibel app. It is easy to use and very responsive to changes in sound. I am using it to evaluate sound levels in relation to selection of HVAC and ventilation systems for a new commercial office building.

### 5/5 — Amazing

*2014-08-09*

Used this app to calibrate my 7.1 home theater to 75db on each speaker.  It's super easy to use. I found it to be the best to use by setting it on slow and C.

### 5/5 — Very practical app

*2014-04-06*

I found this app very useful, it is more practical than other apps I paid for. I use professional Sound Level Meters in my work and this app came handy for rough estimation of Laeq,t and La99. One suggestion for improvement is to enlarge the restart and hold buttons.

### 5/5 — Great app

*2013-09-14*

Simple and accurate. Very informative without being complicated. Totally worth the money.

### 5/5 — OUTSTANDING !!!!

*2012-05-27*

I do commercial audio work and run audio for our church.  Typically I use a handheld meter to check db readings of the system.  I've tried numerous apps and none really did the trick.  Some had great graphics, whistles ands bells, etc. etc. but as far as ease of use, accuracy and ongoing dependability this one beats the rest hands down.  You can adjust the reading by comparing it with another instrument, but generally the comparison with a professional hand held and this app is probably + / = 3 db, if that.  It's close enough for me, as I have a range I try to keep the church audio and this app consistently gives outstanding reliable readings.  I run the app throughout the service and I'm able to keep up with where the levels should be.  I'd have to say this everything I could ask for...and more, in an app.  It allows me to have the Ipad sampling the sound continually, vs. having to keep restarting my handheld.  The "professional" unit now stays in the case...and only gets used occasionally.  (I normally don't write app reviews...but this one is well worth getting...very well designed!)

### 5/5 — Outil indispensable !

*2012-03-03*

Dispose d'une fonction absente de la plupart des applications équivalentes sur iPhone : La mesure du volume sonore moyen sur une période. Indispensable pour moi ! Bravo.

### 5/5 — Indispensable !

*2012-02-22*

Sonomètre précis, très simple a utiliser, que demander de plus ? Avec cette application votre iPhone devient un sonometre pratique pour régler un home cinema par exemple ! Je recommande !

## Frequently asked questions about logSPL

### What is logSPL?

logSPL is a full-featured sound level meter designed for iPhone, iPod, and iPad. It provides basic and advanced features for measuring and analyzing noise levels, including real-time data and historical curves.

### How accurate is logSPL?

For best accuracy, logSPL recommends calibrating the app against a reference. Users can add or remove a fixed offset to the measured values via the Mic. tab to fine-tune precision.

### What weighting options does logSPL offer?

logSPL offers three weighting options: 'A' for evaluating human perception of noise, 'C' for a broader frequency range, and 'Z' for minimal filtering, balancing audio systems.

### Can logSPL be used offline?

The description does not specify offline functionality. However, as a measurement tool, it is likely to function without an internet connection once installed.

### What are the advanced features of logSPL?

Advanced features include computing L% values (L95, L50), dosemetering with user-set thresholds, and displaying a real-time histogram. These are intended for advanced users due to their complexity.

### How often is logSPL updated?

The app was last updated on November 25, 2023, indicating active development and maintenance. The latest version is 4.6.

### What devices support logSPL?

logSPL is compatible with iPhone, iPod, and iPad devices. It adapts to different screen resolutions, including HD and Retina displays.

### Does logSPL have ads?

No, logSPL does not contain advertisements. It is a paid application, and the provided data indicates it is ad-free.

## Version history (last 5 releases)

### 4.6 — 2023-11-25

Re-compiled for latest iOS. Better handling of various screen sizes and shapes.

### 4.5 — 2022-02-20

Re-compiled for latest iOS. Better handling of various screen sizes and shapes.

### 4.4 — 2020-01-15

Optimized for latest iPhone (11) and iOS (13).
Note that natively iPhone 11 does NOT support upside down mode (same for all Apps: Safari,...).

### 4.3 — 2017-03-01

Re-compiled with latest iOS

### 4.2 — 2016-02-10

Minor update.
iPad users will probably be invited to re-run the 'SET' procedure, when available.

## Apps similar to logSPL

| App | Rating | Price | Category |
| --- | --- | --- | --- |
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| [Decibel X PRO: dBA Noise Meter](https://appshunter.io/ios/app/decibel-x-pro-dba-noise-meter/id1257651611) | 4.7 (6,903) | $69.99 | Utilities |

## More apps by Fabien Lefebvre

- [Speaker Meter](https://appshunter.io/ios/app/speaker-meter/id338004164)
- [Diapason Audio Generator](https://appshunter.io/ios/app/diapason-audio-generator/id352091730)
- [SPLnFFT Noise Meter](https://appshunter.io/ios/app/splnfft-noise-meter/id355396114)
- [AeroGoto](https://appshunter.io/ios/app/aerogoto/id542983237)
- [BetonMix (concrete calculator)](https://appshunter.io/ios/app/betonmix-concrete-calculator/id872695788)

All apps by Fabien Lefebvre: https://appshunter.io/developer/338004167

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-06.*