Syn-Aud-Con Impulse Response Utilities

This page has been created to aid in learning to collect Room Impulse Responses (RIR) using a simple recorder and some freeware software programs. Syn-Aud-Con makes no guarantees regarding this content and assumes no liability for its use or abuse.

This PDF gives an introduction to the process of RIR gathering.

http://www.synaudcon.com/irexch/files/nl053_sbsd.pdf

Support Resources

You will need a WAVE file editor for working with RIRs. Excellent freeware editors are Audacity and  WavePad. Another excellent WAVE editor (not freeware) is Sony SoundForge Audio Studio.

RIRs can be played back in any wave editor. They can also be convolved with dry program material to see how it would sound if it were radiated and gathered in the same manner as the IR. A free convolution tool written especially for this purpose is GratisVOLVERTM.  Here is a dry speech file (both 44K and 48K sample rates) for you to experiment with:

http://www.synaudcon.com/irexch/files/dry_speech.zip

NEW!!! Use GratisVolver to Extract Impulse Responses!

This PDF explains how.

http://www.synaudcon.com/irexch/files/IR_Process.pdf

This ZIP file contains the required waves.

http://www.synaudcon.com/irexch/files/GratisWAVs.zip

Post-Processing the RIR

Once the RIR is collected, it can be post-processed in a number of acoustical measurement platforms to yield acoustic metrics such as reverberation time, clarity and the Speech Transmission Index. Recommended programs include

EASERA

Arta

Smaart Acoustic Tools

Praxis

WinMLS

In fact, any platform that supports WAV files will work.

Projects

Some project data including IRs can be downloaded from the Syn-Aud-Con IR Exchange at www.synaudcon.com