Audio Waveforms

[BetterRed]

As compared with the Proteus, the Procyon only supports the sinewave.
The reason given in a previous post: http://www.mindplacesupport.com/foru...ble-on-Procyon is the 8 to 16-bit shift.
Perfectly understandable for other complex waveforms (ramp, triangle, user-defined etc). But why not include a squarewave? This will take no more memory up if the system used 4, 8, 16, 32,... bits to define the shape. And according to some studies, a square binaural will produce higher eeg's than any other waveform.
I realise that this could be done via audiosync, but I cannot see why it is not built in.
In anycase i have ordered the device, and look forward to trying it out.

[Marisa]

And according to some studies, a square binaural will produce higher eeg's than any other waveform.

Care to share what studies those were?

[BetterRed]

Care to share what studies those were?

Robert mentions a study here:
http://www.mindplacesupport.com/foru...ght=isochronic
in which pulsed tones create higher eeg's than sines.
I have seen this stated in at least one other paper, but cannot find it right now.
But my point was really that, since the synthesising of square waves would cost the Procyon nothing (more or less) in memory usage, why not include them?

[BetterRed]

Ok, on further reflection (and a couple of pints of beer), it is possible that the Procyon will need just as much memory for a square wave. It doesn't theoretically need them - but in practice might, for example if the design is such that the processor (D/A converter) expects a 16-bit number for the next value, then even if this value is zero (or 'one') it will need a 16-bit number to be returned from the waveform address - though 15 of those bits are redundant.
So, I will adjust my request. Instead of always having both waveforms present, give the user a choice to dl firmware that consists of one or the other. Or else firmware that takes away so many sessions, instead giving the user a choice of BB waveforms.
I cannot think that this would be a major software alteration - and the hardware will not need touching.

[brewmasher]

Yes, square waves will produce the strongest cortical response. But they also produce harmonics within the brain which may not be desirable in most cases. I think you mean square isochronic tone waves, since binaural beats are created inside your brain, and the waveform can't be controlled. Straight square wave isochronics sounds like an annoying click. Most programs use a modified square or a semi- sine wave.

The sine waves mentioned in the aforementioned post is referring to the waveform of the light pulses.

[BetterRed]

Ok, if the reasoning is that pulsed tones will create problems due to the (theoretically) infinte number of harmonics produced.
But if it actually works, in as far as inducing eeg potentials (whereas a sine wave really does nothing), then if not included the Procyon looses its whole Raison d'?tre, at least in the audio sense.
Let the user decide!

[BetterRed]

Yes, square waves will produce the strongest cortical response. But they also produce harmonics within the brain which may not be desirable in most cases. I think you mean square isochronic tone waves, since binaural beats are created inside your brain, and the waveform can't be controlled. Straight square wave isochronics sounds like an annoying click. Most programs use a modified square or a semi- sine wave.

Well a pulsed tone does not sound like an annoying click. Ok it doesn't sound as pleasant as a sine, but if it does the job.....

[brewmasher]

Well a pulsed tone does not sound like an annoying click. Ok it doesn't sound as pleasant as a sine, but if it does the job.....

Yes, it will do the job. So will a drum beat. I don't think that listening to clicks for 30min would be too relaxing.

(whereas a sine wave really does nothing)

Nothing? Consider this quote taken from the Fredericks study
"Both auditory and visual
stimulation were sinusoidally modulated, which eliminated possible stimulation effects
due to harmonic frequencies. A sine wave modulation only produces the designated
fundamental frequency (Sears, 1950)."

A sine wave is pleasant and relaxing to listen to, and will only produce the frequency presented. It is only slightly behind square in effectiveness. It is my choice for alpha and theta programs. I only use square for beta and gamma.

[BetterRed]

Yes, it will do the job. So will a drum beat. I don't think that listening to clicks for 30min would be too relaxing.

Nothing? Consider this quote taken from the Fredericks study
"Both auditory and visual
stimulation were sinusoidally modulated, which eliminated possible stimulation effects
due to harmonic frequencies. A sine wave modulation only produces the designated
fundamental frequency (Sears, 1950)."

But those were not BBs. I do not think the Procyon can synthesise a sine modulated carrier signal.

Nothing?

It was a mistake to write that, and I apologise. The paper I was referring to was not a recent one, as far as remembered, 'cos i can't find it - but it did infer a much greater eeg potential is 'generated' by a pulse i am sure.

According to the paper written by:
Measures of EEG in the context of long-term audio-visual stimulation
M. Teplan, A. Krakovsk?, S. ?tolc many of the older studies failed to take non-linear effects into account. There also seems to be a benefit to taking eegs from more than one reference point. It is not apparent which method of audio stimulation is used, but given they had a commercial AVS system it could be BBs.

[brewmasher]

But those were not BBs. I do not think the Procyon can synthesise a sine modulated carrier signal.

Correct. They are referring to the light flashes. The Procyon uses a sine wave for photic stimulation. BB are formed by presenting a steady tone at one pitch to one ear, and another to the other ear. The difference in pitches are perceived as a beat inside the brain, so the "waveform" is up to the individual.