Dear all,
I recently wrote a script (attached at the end of this email) that, for
each .wav file in the folder/directory where the script is run:
1. smoothly pans the audio from left to right over its full duration for
spatial effect (such that x is mapped both to time and space).
2. exports the file as a .ogg file, saving memory (without noticeable
loss in quality).
In order to make use of the script, you will have to save sonifications as
.wav files after generating them. Run
`my_sonification.write(file_name.wav)` after running
`my_sonification.sonify()` to save the sonification as a .wav file that can
be played at a later time, shared with others, etc. Replace
'my_sonification' with the relevant variable and 'file_name' with whatever
name you choose. Note that Web browsers and audio players should be able to
handle the .wav file on your system.
The script also has two additional dependencies before it can be used:
1. FFmpeg (Use `conda install ffmpeg`)
2. PyDub (Use `pip install pydub`)
Once you've installed the dependencies, navigate to the folder that
contains your .wav files (using `cd path_to_folder`), start your IPython
session by typing `ipython`, and run the script using `%run
pan_and_compress.py`.
If the script runs successfully, then all of the .wav files in the folder
should have been converted to .ogg files that have spatial audio (panned
across the left and right channels) and that are much smaller in size than
the original .wav files.
You can then open the .ogg files in a Web browser or audio player to hear
the audio. Using headphones can make the sonification sound more immersive
as the sound moves from left to right as it plays. Based on the perceived
location of the sound at any given point, you can estimate your position in
the sonification (e.g., you hear a peak halfway through the audio (in the
center) or about a third of the way into it (to the left)).
If you would like to play your new .ogg file in the IPython command line
directly (to avoid the need for other programs), use the following steps:
1. Run `import subprocess`
2. Run `subprocess.run(['ffplay', '-autoexit', 'file_name.ogg'])`
Note that you can hit the Escape key on the top left of your keyboard to
stop playback at any time while the sonification is playing from your
terminal using the above steps. Consider using headphones however/wherever
you choose to play the file.
You will find 1) the script 'pan_and_compress.py' and 2)
'sample_spatial_sonification.ogg' attached to this email. You can listen to
the sample spatial sonification to get an idea of the left-right panning.
Remember to move the script into the folder where you would like to use it.
Please let me know if you try it out and/or if you have any questions.
Best,
Nikhil
P.S.: The sample sonification is of the mathematical function the cosine of
*x* squared, *y* = cos(*x***2), from *x* = -6 to *x* = 6. Python uses two
stars to indicate exponentiation.
