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## Room Impulse Response Generator

version 1.3 (2.04 KB) by

This program calculates the acoustical impulse response of a rectangular room

Updated

This function calculates a room's impulse response for an arbitrarily positioned sound source in an arbitrarily dimensioned rectangular room, as it would be heard at an arbitrary position. The output of RIR.m is a vector and can be used as an FIR filter to produce a reverb effect. To implement this filter you will need to do a fast convolution. I have another program, FCONV.m that performs this task. It is available on the Mathworks File Exchange.

For instructions on how to use this function, put RIR.m in your Matlab work folder and type "help rir."

The physics theory used by this function is not perfect. However, the function was intended to be used for space rendering in audio productions, and for this it works pretty well. For an article detailing the theory used go to http://www.sgm-audio.com/research/rir/rir.html.

The following was taken from an email. It regards the input variable N.

"...During the computation, the end of the reverb tail gets cut off. The variable N relates to how long the tail is prior to the cut off. If N=6 then some echoes that have undergone more than 6 reflections and will be unaccounted for. Additionally no echoes that have undergone more than 3*N=18 reflections will be accounted for. You may use any value of N you like. However, small N may mean that the impulse response is shorter than the Sabine reverb time, and large N may mean that it is longer..."

As for the reflection coefficient R, I usually use a positive value. However, a negative value for R will produce an output that more closely resembles more traditional impulse response calculations.

Augusto Carvalho de Sousa

### Augusto Carvalho de Sousa (view profile)

Nice one!

I have a question: after I make the simulation, I want to make a .WAV file of tie IR I generated. I am trying to use audiowrite but it is not working. Any thoughts?

Cheers!

Ali Rakhman

### Ali Rakhman (view profile)

very good , but i really need the paper, the link that the author mentions isn't working, can anybody give me the paper , thx

Juanlo Alonso

nguyen

### nguyen (view profile)

Jie Yang

It's so very useful for acoustic simulation.

Ismail Al Anshori

There's some restrictions in the physical modelling, but I think this is good enough.

John Smith

Mark Cooke

very good IRs when used as audio processing for music.

Karin Vogt

Super good documentation togehter with a paper on the formulas