iPad Screenshots


"Onmon" is Spectrogram Analyzer app for Audio and Voice band.

It uses the Fast Fourier Transform (FFT) processing to analyze incoming sound signals and provides a precision frequency response measurement for the spectrogram analysis.

"Onmon" is a visual representation of the spectrogram of frequencies in a sound as they vary with time in the frequency range of 24kHz from 20Hz.

The spectrogram is a graphical image with two geometric dimensions that the horizontal axis represents time and the vertical axis is frequency, and the addtional third dimension is indicating the amplitude of a particular frequency at a particular time that is represented by colour of each point in the image.

This app has two analysis modes, Audio mode and Voice mode.
Audio mode performs a real-time spectral analysis as the target of audio signal by Spectrogram and Spectrum. It can be used for discovering visual hidden images in the various sounds, such as music, birdsongs and environmental noises. You can also be used to capture an unpleasant high-frequency noise in your sound system.

Voice mode performs the frequency domain analysis as the target of voice signal, which can be displayed simultaneously Spectrum, Cepstrum, Envelope, Formant and Spectrogram. It can be used for visualization analysis of voices, speech, vocal, and squeaking sound of the animal.

In addition, this app is equipped with the replay function, so you can see the spectral analysis results offline.

- FFT: 4096 points/frame.
- Sampling Rate: 48kHz/sample (maximum measurements frequency: 24kHz).
- Spectrogram analysis. (horizontal-axis:time, vertical-axis:frequency, color-image:amplitude)
- Spectrum analysis.
- Display Capture function. (Snapshot : Storage image file in PNG format)

[Audio mode]
- Spectrogram display.
- Spectrum response display.
- Frequency bandwidth : 24kHz, 12kHz, 6kHz, 3kHz, 1/12 octave band.
- Time resolution selection (L/H) : When high time resolution "H", the frequency bandwidth becomes 1/2. (12kHz, 6kHz, 3kHz, 1kHz)
- Dynamic range of Amplitude display: 120dB
- Pan to adjust visible amplitude ranges (Range:0dB/-30dB)
- Peak-level Hold function. (Hold)
- Replay function with offline analysis.(Set/Play)
- Measurement time : Up to 180 seconds.

[Voice mode]
- FFT Spectrum display.
- Spectrogram display with graphic view control.
- Cepstrum display.
- Envelope display
- Formant display : 1st, 2nd frequency
- Replay function with offline analysis.(Set/Play)
- Measurement time : Up to about 45 seconds.

At the time of the first access to Microphone and Photos 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 > Photos or Microphone".

Please visit our iOS App Support page for more information on this app.

TOON,LLC is a company that seeks the comfort of sound environment based on our acoustic proprietary technology, and we will provide tools for audio professional, sound technology, home theater installer, and anyone who loves audio.

What’s New

Version 5.0

- Added time resolution selection. (Audio mode only)
- Some minor improvements.
- Changed Screen design.
- Requires iOS11.4 or later.

App Privacy

The developer, TOON,LLC, has not provided details about its privacy practices and handling of data to Apple.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


598 KB

Requires iOS 11.4 or later. Compatible with iPad.



Age Rating


  • Family Sharing

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

More By This Developer

You May Also Like