Support / SLA Lite

Sound Level Analyzer Lite


"Sound Level Analyzer Lite" is a sound level meter app for iPhone. It is a free app that has simplified the function of "Sound Level Analyzer PRO".

Available in variety of applications as the neighboring environmental noise measurement, audio system check, vehicle interior noise check, sound check of live events, and more.

This app can easily set the frequency weighting characteristic and the time weighting characteristic necessary for sound level meter, and appropriate sound level measurement is possible. It also has the calibration function to adjust the microphone level for each device.

The WHO has proven direct links between noise and health risks; tinnitus, sleep disturbance, stress, cognitive impairment, heart diseases and annoyance in general. Please check your environmental noise for your wellness.

In the latest version, the UI design has updated, and Time course graph function have been added as a new feature.

sla lite

"Sound Level Analyzer Lite" comes pre-calibrated for the typical iPhone built-in mic, but you can adjust the calibration if you have a calibrated standard sound level meter.

"Sound Level Analyzer Lite" has received the highest rating as a sound level meter app in the research paper of acoustic academic journal "Applied Acoustics". (Paper: ”Testing the accuracy of smartphones and sound level meter applications for measuring environmental noise”, Enda Murphy, Eoin A. King ; Applied Acoustics 106(2016)16-22.)

In addition, the high-end app "Sound Level Analyzer PRO" has a powerful sound / noise analysis function in addition to the sound level measurement function, so please consider using this app for your advanced requirements.

Please to click the following link to Free download "Sound Level Analyzer Lite" from App StoreTM. It will be open the download page on App StoreTM.

It will move to another site, download from Aplle Store

Installation of iTunes is required.
Communications charges when connecting to the App Store will be borne by the customer.
* iPhone is a trademark of Apple Inc., registered in the U.S. and other countries.

* App Store is a service mark of Apple Inc.

Products Information

Version : 3.2
Release date : May 18, 2018. UTC
Size : 2.8 MB
Recommendation : Requires iOS 11.3 or later.
Category : Utilities, Life style


Sound Level measurement :

- Leq :equivalent continuous sound level

- Lavg : Long-term average equivalent sound level

- Lmin : Minimum sound level of Leq

- Lmax : Maximum sound level of Leq

Time course graph function :

- Bar chart : "Leq"

- Green line : "Time average level, Lavg"(All time)

- Orange line : "Moving time average level"(5 sec)

Display level dynamic range : 0 - 130dB
Supports frequency weighting filter : A, C, and Z (non-filter).
Supports Time weighting : 125ms (Fast), 1.0sec (Slow)
Frequency range: 20Hz - 20kHz
Calibration function : offset value from -20dB to 20dB (1dB-unit)
Display resolution : 0.1dB
Peak measuremet range : around 110dB (by built-in mic perfomance)
Pause the screen during Measurement
Measurement duration : 20sec


"Sound Level Analyzer" can be used in applications such as the following:

Live Sound
Environmental noise measurement
Setting and Tuning of Audio system
Installation of Audio equipments
Installation of Car audio equipments
Architectural acoustics
Device management

In addition, the followings are examples of the magnitude of the sound level in the measurement of environmental noise.

130dB : Engine sound of Airplane
110dB : Horn of Car
100dB : Noise of passing train
90dB : In loud factory
80dB : In the train, Vacuum cleaner
70dB : Noisy office, Noisy street
60dB : Quiet Car, Normal conversation
50dB : Quiet office
40dB : In the library, Quiet residential area
30dB : Outskirts of midnight, Whisper
20dB : Sounds of rubbing leaves

Sound Level Measurement

It makes the sound level measurement in general. In this case, by applying the appropriate Frequency Correction, Time Correction, and Level Correction, you can be the best sound level measurement.

By tapping play button to start the sound level measurement, and it then pause by tapping it again.

The access permission to the microphone will be confirmed from the iOS system at the first start-up. Please enable access to the microphone.

Sound level measurements are displayed measured values​of Equivalent continuous sound level (Leq), minimum value (Lmin), maximum value (Lmax) and Time average equivalent noise level (Lavg) in dB units. The Leq is also displayed as a bar graph.

Time course graph of the sound level is also displayed. This graph is the sound level fluctuation for the last 20 seconds. The contents of the graph display are as follows.

Black bar : Equivalent continuous sound level, Leq
Green line : Time average level, Lavg(All time)
Orange line : Moving time average level(5 sec)

slalite_c slalite_z

It can be measured as parameters, Time weighting correction, Frequency weighting correction, and Level calibration, to set as follows:

Generally, when using as a noise level meter, please set parameters for A correction and FAST.

[Time weighting correction]

It specifies the time constant of calculating the sound level. Please set in accordance with the occurrence tendency and type of sound source.

FAST : 0.125 sec (Default)
SLOW : 1.0 sec

[Frequency weighting correction]

It is a weighting filter that limits the frequency band of the input signal. Please set according to the measurement applications.

A : A correction - The noise measurement by general audibility correction (Default)
C : C correction - Sound pressure level measurement for wideband sounds and music
Z : Non correction

[Level Calibration]

You can specify the reference level in the offset range. Tap the "Set&Info." button, the calibration input window will appear. If you have a standard sound level meter, please use it to adjust the reference level.

Offset ranges : -20dB to +20dB in 1dB unit

Product Information

By tapping "Set&Info." button, it is displayed the product information link and the feature description. If you tap the "Support/Info", Safari starts and you can see our support page. If you tap the "Upgrade info.", you will see our App's information on the "App Store".

By tapping "close" button again, it will return to the previous measurement view.

Release Information

Version 3.2 was released on May 18, 2018. UTC
Version 3.1 was released on March 16, 2018. UTC
Version 3.0 was released on February 27, 2018. UTC
Version 2.4 was released on January 23, 2018. UTC
Version 2.3 was released on May 17, 2017. UTC
Version 2.2 was released on June 2, 2016. UTC
Version 2.1 was released on March 4, 2016. UTC
Version 2.0 was released on December 21, 2015. UTC
Version 1.4 was released on December 4, 2015. UTC
Version 1.3 was released on March 24, 2015. UTC
Version 1.2 was released on September 3, 2014. UTC
Version 1.1.1 was released on July 13, 2014. UTC
Version 1.1 was released on June 23, 2014. UTC
Version 1.0 was released on June 10, 2014. UTC


At the time of the first access to Microphone after installing the app, you will be asked authorization to access them by the iOS system. If you have not enabled this setting, the app can not access them by privacy restrictions of the iOS system. Please enable the access permission on the iOS setting, "Settings > Privacy > Microphone".

This app is adjusted the reference value for iPhone. However, the built-in microphone of your iPhone is likely to have a non-uniform gain. The more exact measurement should be calibrated using the absolute level calibration devices.

Request for review

Please send a review of your comments and requests for this app. We will use your review to improve our products. Thank you for your cooperation.

It will move to another site, download from Aplle Store Please send a review message for "Sound Level Analyzer Lite".

Please fill in your review by accessing from iOS device.

Contact us

Inquire about this app please from below! Please contact us with the following details if you have any requests or problems.

1. Application name
2. Device model
3. iOS version
4. Country you live
5. Details about your requests or problems.

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