pyrirtool

Measuring room impulse responses with python and sounddevice

The code is based on the exponential sine sweep method and its modifications, proposed by A. Farina [1, 2]. The python package sounddevice is used for recording and playback.

Getting started

Required packages

• Utilities: os and argparse
• Computing and signal processing: numpy and scipy
• Recording and playback: sounddevice
• Plotting and vizualization matplotlib

First steps

The main file used to record a room impulse response is measure.py. When running it for the first time from the terminal, a file with default parameters is created in _data/defaults.npy (recording doesn't take place when running the script for the first time.)

=> python measure.py
Default settings not detected. Creating a defaults file in _data

After default settings have been generated, they can be checked by typing

python measure.py --defaults

The output should be (the different parameters will be explained later)

amplitude => 0.2
duration => 10
startsilence => 1
endsilence => 1
reps => 1
fs => 44100
inputChannelMap => [1]
outputChannelMap => [1]
inputdevice => 0
outputdevice => 1
sweeprange => [0, 0]

Configuration from the command line

Some of the measurement settings can be passed as command line parameters. To see available options type

python measure.py --help

Selecting the audio device

To see a list of available input and output devices, with the corresponding number of input and output channels type python measure.py --listdev in the terminal. The output looks something like this:

=> python measure.py --listdev
> 0 MacBook Pro Microphone, Core Audio (1 in, 0 out)
< 1 MacBook Pro Speakers, Core Audio (0 in, 2 out)
Default input and output device:  [0, 1]

If there are other devices available they should appear in the list as well. Then, desired input/output devices can be selected using their corresponding number in the list, and the keywords -indev (for input device) and -outdev (for output device). For example:

python measure.py --setdev -indev 0 -outdev 1

Measuring a room impulse response

To start a recording from the command line with custom parameters, type:

python measure.py -dur 2 -r 2 -a 0.5 -ss 2 -es 1 -chin 1  -chou 2

• Setting the sine sweep duration to 2 seconds: -dur 2

• Choosing the number of sweep repetitions-r 2

• Setting the sweep amplitude: -a 0.5

• Setting the silence at the start and at the end of a sweep (e.g., 2 seconds and 1 second, respectively): -ss 2 -es 1

• Setting the input and output channels (for example to channel 1 and channel 2, respectively) -chin 1 -chou 2

• One can also record multiple channels simultaneously, for instance by setting -chin 1 2 3 (if the channels are available). The number of available channels can be seen by typing measure.py --listdev

References

[1] A. Farina, Simultaneous Measurement of Impulse Response and Distortion with a Swept-Sine Technique, 108th Audio Engineering Society Convention, 2000

[2] A. Farina, Advancements in impulse response measurements by sine sweeps, 122nd Audio Engineering Society Convention, 2007

Authors

pyrirtool developed by Maja Taseska at KU Leuven, ESAT-STADIUS.

License

This project is licensed under the MIT License - see the LICENSE.md file for details