Acoustic Facts 4+

Reverberation time calculator

Acoustic Facts

Designed for iPhone

    • 599,00 kr

iPhone Screenshots


This app turns your iPhone into a high-quality measurement equipment for reverberation time measurements. Reverberation time is a measure of how long a sound persists in a room after the sound is turned off, i e a measure of the room echo.

The techniques and algorithms in this app follow the international measurement standard ISO 3382-2 and measures reverberation times in the octave bands between 125 Hz and 4 kHz, which are the most common frequency bands used for most rooms. The algorithms are validated against the laboratory standard ISO 354 for best accuracy. Any impulsive sound can be used as source, e g a handclap, a dropped book. For best results use the specially designed impulsive source provided by Acoustic Facts (see our website

The measured values can be used as input in the room acoustics web tool that can be found at At the site there are ample products that are validated and that can be used to modify the reverberation time.

What’s New

Version 1.3

Fixed a bug causing problems sharing the report on iOS 13.

App Privacy

The developer, Acoustic Facts, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary based on, for example, the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

You Might Also Like