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Audio Test Tone Generator

Professional quality sound signal generator for audio engineers to test equipment using their AndroidTM device.
  • Multiple wave forms: Sine, Triangle, Square and Sawtooth.
  • Custom frequency selection from 2 Hz to 20 kHz.
  • Frequency Sweep.
  • Noise: White, Pink and Brown.
All signals are generated in real-time and the application can run in the background.
A setting allows you to decide whether the tone generator should automatically stop when you receive an incoming call.  Hence the only special permission the App requires on your device is the ability to determine whether you're on a call or not (READ_PHONE_STATE).
Help documentation is built in to the App (no network access is required).

Requires Android OS version 2.3.3 or later.
Available now on Google's Android Market priced at 4.99 GBP.
Listed under Multimedia apps or use this QR code.  Larger QR code is at the bottom of this page.

By default a 'damage warning' is displayed each and every time you press the Play button.  This warning can be disabled in the Settings once you get used to how the application works.
Output is 16 bit, mono and is rendered at the highest sample rate supported by Android on the device (typically 44100 Hz).

Level Adjustment and Calibration

A couple of users have been in touch to request the ability to either apply a digital pad to the output level or to be able to calibrate the output level.
The software currently outputs the wave forms at the maximum peak to peak amplitude that can be generated in 16 bit samples without clipping. Output level can only be set using the 'Media volume' control provided by the Android device. It is up to the device manufacturer as to how they implement this in respect of both hardware (DAC and possibly VCA) and software (audio driver). For this reason the scale is neither accurate or defined!
We are considering adding calibration to the software but are working on how to do it cleanly. If you have thoughts in this respect then please get in touch.

Screen Shots

These were grabbed from a Google / HTC Nexus One during our testing:

Update History

v.1.2.0 - 23 July 2014

  • Fixed waveform preview display (it was inverted).
  • Fixed user interface layout issues on devices with larger screens (e.g. tablets).
  • Improved quality of icons on higher resolution screens.
  • Added notification when the generator is running in the background.
  • Implemented some other minor usability enhancements.
  • Increased minimum Android version requirement from 1.6 to 2.3.3.

v.1.1.1 - 27 January 2011

Added some new features inspired by feedback from users:
  • When playing you now get a preview display of the generated waveform.
  • Presets wave frequency selection view offering the standard frequencies an engineer is familiar with (i.e. those on a 30 band EQ).
  • Explore wave frequency selection view with Coarse and Fine sliders. Perfect for finding that frequency that's feeding back, resonating or otherwise honking!

v.1.0.1 - 27 July 2010

Update to look at performance issues, improve accuracy of the pink noise generator and make the UI a little prettier.  Thanks to Susan Parker (Audiophonics) for her valued (and continuing) feedback.
  • Cosmetic improvements to main UI
  • Current tone type and frequency are now displayed when the generator is stopped
  • Nicer display of generator CPU use statistics
  • Added option to set number of IIR filter poles for pink and brown noise
  • Added option to automatically stop if stuttering
  • Added option to set buffer size from multiple of one to four (was previously fixed at one)

v.1.0.0 - 20 July 2010

Original release.

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