AudioTools is a suite of professional-grade audio and acoustic analysis apps. Included in the price of this app is a great collection of professional tools -- SPL, RTA, FFT, Speaker Polarity Test, Generator, Audio Scope, CLF Viewer, and Recorder, and the framework to add more powerful modules as you need them.

Customize AudioTools for your needs by buying any of the additional optional modules, like Smaart Tools I, SPL Graph, or Impulse Response, at any time right from your iOS device.

We test every iOS device and calibrate the microphone level and frequency response for the best results. We have the ability to turn off the Apple low frequency filters, and on many devices we can measure up to 120 dB SPL.

Add iTestMic, iPrecisionMic, or iAudioInterface2 for a complete professional audio and acoustic test and measurement platform.

Actual reviews:

“...AudioTools is a “how did I ever live without it” app”.

“I think this application is the best I EVER purchased.”

“I have used many thousands of dollars of complicated test equipment that doesn’t measure up to this app suite.”

***** Included in the app price *****

* SPL Meter
A faithful reproduction of a classic analog SPL meter. Includes A and C weighting, and Fast and Slow ANSI decay modes. All filters meet or exceed ANSI type 1.

A 1/3 and octave band Real Time Analyzer. Includes touch-GUI range control, a cursor, max/min bars, and noise curve overlays.

Detailed acoustic analysis, up to 32876 points. View full detail or smooth to 1/24, 1/6, 1/3 or octave. Includes cursor, scalable graphics, and peak tracking.

* Polarity
Speaker polarity checker. Route the test signal to a speaker, and read the polarity of the speaker on the screen.

* CLF Viewer
Show loudspeaker data, including plots for impedance, axial response, sensitivity, polar response, and 6dB coverage, and a 3D color balloon plot.

* Delay Finder
Measures the time it takes for a pulse to return from a speaker.

* Generator
Generates sine waves, square waves, white and pink noise.

* Line Level Tests
A line level measurement function and frequency counter.

* Audio Scope
A dual-channel audio oscilloscope that includes auto-triggering, variable gain and sweep rate, and storage of scope images.

* Recorder
A mono/stereo audio recorder with WAV and compressed formats and 8k-48k sample rate. Transfer files via WIFI.

* File transfer of results via wifi to PC / Mac.

* Audio Calculators

***** Optional modules available for purchase from within AudioTools *****

* Smaart® Tools - Single channel module.
The power of Smaart® on a mobile platform. Includes RTA graphs to 1/48th octave and Spectrograph. Split-screen on iPad.

* Transfer Function -- Requires 2-channel interface.
Two-channel FFT-based measurement. Allows you to analyze sound system performance with music or pink noise as the signal source.

Energy Time Curve. Plot decay of an impulse over time, and compute RT60 time. Internal or External trigger.

* Impulse Response
Record and analyze an impulse or sine sweep, compute octave and 1/3 octave ETC, T30, C50, C80, CT, Definition. Also shows FFT and Schroeder curve.

Fast and accurate sine-sweep measurement of loudspeakers and rooms.

* SPL Pro
Digital SPL meter with ANSI Slow, Fast, Peak, and Impulse mode, along with LEQ. Includes A and C weighting, and all 10 octave band filters.

* SPL Graph
Plot second-by-second SPL level for up to 24 hours, and optionally record the audio. Also, add the optional Octave Band Logging upgrade to elevate this tool to rival any professional logging SPL Meter.

* SPL Traffic Light
Monitor live sound levels SPL and Leq and see status in a simple green-yellow-red display.

* STIPA Speech Intelligibility
Meets the current NFPA code standards for testing evac systems and schools.

* Speaker Distortion
Measure THD+n of any driver.

* THD+n (requires iAudioInterface)

* Impedance Meter and Plot (requires iAudioInterface)

* Phase Meter

* Amplitude Sweep

What's New

Version 10.17

-Updated in-app purchases for Remote Noise Monitoring
-Bug fixes and stability improvements

Ratings and Reviews

4.8 out of 5
1.4K Ratings
1.4K Ratings

Awesome app


I’ve used this app for years now and have not rated it but it has always been up in the 4-5 star range. Great updates and quick to fix any bugs. I thought I bought the SPL pro once but it never transferred to my newer devices. I could be wrong it was quite a while ago, but everything else has always transferred with all my new devices. I found that there is an option to restore purchases but I did have to click the SPL pro button first for the choice to restore to come up.
Andrew did respond but I had already figured it out. Thanks for your help and quick response.

Developer Response

Everything should come back with the Restore Purchases function, unless you had some in-apps that were bought from another App Store account.

Misleading money-grab


Really wanted to like this app. I read about all these different tools it supports in the description, and decided to pull the trigger on the most expensive app purchase of my life. Twenty dollars. Turns out that this only gets you a couple of simple "tools", most of which are available for free through other apps. The kicker is that the useful tools can cost anywhere between 5 and TWO HUNDRED DOLLARS. Who do these guys think they are? It's absolutely insane. Not even those videogames with endless "microtransactions" are this much of a shameless money steal. When you pay twenty dollars for an app, it had better be good. It shouldn't just be a portal to dropping another absurd amount of money for basic functionality you would expect.

Developer Response

We're really sorry that you are not happy with your purchase. AudioTools is designed for professional audio analysis and is priced accordingly. The basic toolset, RTA, FFT, SPL Meter, and Generator, do provide a lot functionality and many of our users never go beyond those for common tasks like live audio mixing, home theater calibration, and sound level testing. The more expensive add-ons provide functionality for specific tasks, such as speech intelligibility, which meet international standards. Please contact us at and we would be happy to work something out for you, since it seems that this tool is not working out for you.

Great app nice features


I only use a small percentage of the app but it is great to have all of this in one place. Plan on getting then calibrated USB mic.

Only current nit — don’t use the screen capture on IOS 11.0.2. If you need that try before you really need it or use the Apple supplied screen capture. On my device you loose most of the third octave bars and it totally clips the top of the graph. Hopefully when I upgrade to IOS 11.2 this will fix itself. If not, how the developers can research.


Andrew Smith
196.8 MB
Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.
English, French, German, Japanese, Polish, Simplified Chinese, Swedish
Age Rating
Rated 4+
© Andrew Smith
In-App Purchases
  1. SPL Pro Module $7.99
  2. Smaart RTA $49.99
  3. SPL Graph Module $9.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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