The Cryosleep Trace Brainwave Generator

The Cryosleep tracer program generates changing noise-waves with a superimposed brainwave. This is done by generating, on average, 480 different frequencies and mixing them together. In contrast to many other brainwave generators, the sounds are nice to listen to and vary over time. The software works currently only for Linux. If sufficient requests exist, we might consider porting it to windows. However, a number of brainwaves are presented below.

Download & Compile

To compile the program the qt4 libraries and qt4 development files are necessary. The location of these programs should be placed in the defines file. Once this is done typing make should suffice. To start the program start Cryosleep in the current directory. There is currently no installation into the filesystem, the binary Cryosleep is all that is necessary. When you started the program you can load one of the tubes found in the tubes directory. These are the parameters used to generate the demonstration waves below.

Demo Sounds

Below are some brainwaves I generated. It might be that the actual frequency is the double of the mentioned frequency.

Program Use

The program has many different options, all useful to change the generated sound waves. Probably the most important is the saving and loading of previous settings with the 'Load' and 'Save' buttons. Predefined settings are stored in the 'tubes' directory of the distribution.

Output

The program can generate a file on disk or can play the file directly (the latter might not always be possible if your computer is too slow). Through selecting 'output is DSP device' you inform the program to play the file to /dev/dsp. Otherwise it will dump the output to the file named in the output text field. If you select the independent stereo channels, then different compositions will be generated for every ear. This can be quite interesting to listen to, and this actually still works with the brainwaves as well.

The generated files: The sound waves generated on disks are '.raw' files. They are 16 bit stereo files. The samplerate is determined by the playing rate. To listen to them a program such as bplay can be used:

bplay -b 16 -S -s <samplerate> Cryosleep-generation.raw

or if you want to convert them to .wav files you can use sox

sox -r <samplerate> -s -w -c 2 Cryosleep-generation.raw

Sound Generator

Random freq/lfo traces: the generator creates white noise through superposition of many different sine waves. For every 'band' there will be XXX sine waves. So if, you choose 5, then, given the fact that we have 24 bands, we will have 120 different sine waves. The larger this number, the more 'noise' like the sound will be. With few traces, the sound will be more synthetic.

Use the 'perfect spectrum': if this box is selected the generated noise will be shaped according to the 'perfect' spectrum. This spectrum is a measurement of 15000 songs and reports the mean strength of every frequency band. This is my favorite option because these sounds sound very natural. If this option is turned of the freq shaping coefficient will be used.

Frequency Shaping Coefficient: the frequency shaping coefficient determines how high frequencies compare in strength to low frequencies. See the demo files for sample values.

Composition

The composition generated by Cryosleep consists of 24 different frequency bands. Every frequency band is filled with noise. This noise goes independently up or down over time. The three options with respect to the LFO synthesizer determine how this happens.

LFO shaping coefficient: determines the amplitude of every LFO trace depending on its frequency.
Lowest LFO frequency: the lowest possible frequency
Highest LFO frequency: the highest possible frequency. If those values are too high then the composition will not sound good. Better is to have very slow oscillating waves.

Brainwave

By selecting the stereo brainwave box, you enable the brainwave generator. The brainwave is superimposed over both channels by making sure that the addition of the left and right channel will equal a sine wave with a frequency specified in the frequency box. Please note here, that this frequency is calculated based on a 44100 Hz samplerate, as such if you specify a brainwave of 10 Hz and play the sample at 22050 Hz, then the brainwave will be 5 Hz. This is still an inconvenience of the program, but hey... i can't fly :)

If you are interested to discuss brainwave stuff, join our mailing list at the Cryosleep Mailing list.