I'd like to collect data on how the different signal generation parameters result in different sensations in order to develop better scripting tools. I would like to ask the community to aid in the research, you can help if you have a stereostim box. I came up with a couple of things that can be tested, but feel free to come up with your own tests if you feel I missed anything.
In all tests, we want to figure out how the sensation changes while controlling for the subjective intensity difference between the two signals. So, adjust the A/B volume until both signals have the same subjective intensity.
Download latest version of Restim here: https://github.com/diglet48/restim/releases
experiment 1: Pulse frequency at low pulse widths. At which frequency does the signal become smooth?.
Background: pulse based boxes and Restim in pulse-based mode sends short pulses with a frequency from 1 to 100hz. Literature says that if pulse frequency is low, (<30-40hz) pulses are felt as independent events. If pulse frequency is high (>60-80hz), pulses are felt as continuous event. Between those frequencies a phenomena occurs that's called 'flutter'.
We would like to know at which point the pulse frequency becomes high enough that the signal becomes fully smooth and discerning between two signals with different pulse frequencies is no longer possible.
Test setup: carrier frequency 1000hz (or other value of your choosing), pulse width 4. Set pulse frequency to different values for A and B (for example 30hz vs 40hz). Adjust the A/B volume until both signals have the same intensity. Can you still distinguish between the A and B pulse?
My results:
Edger477's results:40hz vs 50hz: yes
50hz vs 60hz: unsure, extremely small difference.
60hz vs 80hz: no difference
experiment 2: Pulse width at high pulse frequencies.I can definitely feel difference between 60 and 80, but it does become very subtle. Adjusting intensity to like 94% for 80 makes it so that it is feels the same intensity wise but there is small difference in texture.
Also, I love to use signals above 100hz pulse freq, with narrow pulses, small differences are hard to notice but such high freq pulses feel more and more like pressure, arousing.
Background: in the previous experiment we identified the pulse frequency at which the signal becomes smooth. We would like to know how, and if, the sensation of the signal changes when the pulse width (Restim definition) is increased when pulse frequency is in the 'smooth' region.
Test setup: carrier frequency 1000hz (or other value of your choosing), set the pulse frequency to approximately the value you found in experiment 1 (if you don't know, set 60hz). Select different A/B values for pulse width and pulse rise time, taking care to keep duty cycle below 100%. Adjust the A/B volume until both sigals have the same intensity. Can you still distinguish between the A and B pulse?
My results:
experiment 3: Pulse width at low pulse frequencies.50hz, 2 rise time, 4 vs 18 pulse width: feels identical
50hz, 9 rise time, 4 vs 18 pulse width: unsure, extremely small difference.
50hz, 2 vs 9 rise time, 18 pulse width: feels identical
Background: At lower pulse frequencies, there definitely is a difference between short and wide pulses. We would like to know how the sensation changes as the pulse shape changes at low frequencies.
According to literature, the subjective frequency is determined by the period of silence between the pulses, not the pulse frequency. We would expect to see wider pulses to have higher subjective frequency.
Test setup: carrier frequency 1000hz (or other value of your choosing), set the pulse frequency to 30hz. Select different A/B values for pulse width and pulse rise time, taking care to keep duty cycle below 100%. Adjust the A/B volume until both signals have the same intensity. Can you still distinguish between the A and B pulse?
My results:
experiment 4: carrier frequency..30hz, 5 rise time, 10 vs 4 pulse width: Small difference, unsure how it feels
30hz, 2 rise time, 10 vs 4 pulse width: Big difference. A feels more gentle, more random as if there are multiple layers of movement.
30hz, 10 rise time, 20 vs 4 pulse width: A feels like higher frequency. Can pinpoint location of sensation more accurately.
30hz, 2 rise time, 20 vs 4 pulse width: A feels like higher frequency, like electric toothbrush.
30hz 20 wide versus 41hz 4 wide, 9 rise time: When signal is static, very difficult to tell the difference. When signal is moving fast (circle pattern), A feels more complex, and random, like 10hz rubbing. Very interesting sensation.
It seems that making the pulse wider increases the subjective frequency. Comparing a wide pulse with a slightly higher frequency narrow pulse allows us to compare two signals with the same subjective frequency. For a static signal the difference between two such signals becomes very hard to notice. But when the signal is moving the two signals feel completely different.
Background: In theory, different carrier frequencies target different nerve fibre diameters, therefore changing the carrier frequency should change the type of sensation.
Test setup: Try comparing 500hz to 1000hz or 2000hz and write down your findings. You might need a stronger power supply (more than 12V) to test frequencies above 1000hz.
My results:
Not tested yet
