About volume, yes I use just the master volume on Revo control panel. It's set on about 3/4.
Well yes you pretty much sum it up perfectly in my view phwip. I understand completely what you mean tigre, and I certainly wouldn't perform a whole bunch of tests to get one good result. I do often mess around with the sample for a while first though, because it takes time to learn and concentrate. It's a complete waste of time to start counting results when I still can't hear or even imagine what the difference is. I'm quite confident with my results though, because every now and then I can hear the difference quite easily (for just a few listens at a time), and in this case I always guess correctly. It's all the rest of the time that's tiring and tedious.
But I should keep testing both. What do you mean by how high I can hear? It sounds like frequency, but you are talking about 16 vs. 24bit??
The probability to get 11 correct flips in a row after max 50 tries is max 2%.
RMAA: M-Audio Revolution, 32bit(float), 96kHz.Frequency Response, dB: +0.12, -0.06Noise Level, dBA: -93.9Dynamic Range, dBA: 91.2THD, %: 0.0048Intermodulation, %: 0.016Stereo Crosstalk, dB: -94.9
I don't know, but for me, it was not a waste of time. It lead to interesting discussions. And now, we know better the pitfalls that appear in these kind of listening tests. It is interesting to note that Oohashi's experiment carefully avoided all these pitfalls (Physically double blind test, bi-amplification, listening tests with the ultrasonic content alone, microphone recordings of the ultrasonic content at the listening position, same lowpass filter for the lowpassed version and the full version...).If only it could be repeated by an independant team...
It is interesting to note that Oohashi's experiment carefully avoided all these pitfalls (Physically double blind test, bi-amplification, listening tests with the ultrasonic content alone, microphone recordings of the ultrasonic content at the listening position, same lowpass filter for the lowpassed version and the full version...).If only it could be repeated by an independant team...
Thank you for the link, WmAx, Very interesting.In Oohashi's paper however, a high significance level was shown not only in the brain activity, but also in the subjective evaluation of sound quality by the subjects, as reported in table 2 of the version linked above.This alone can't be considered as a scientific proof until the result is confirmed. It is just a "piece of proof". I was not aware that another team had reproduced the experiment and failed to achieve any positive result.I wonder if the test of Oohashi et al. was flawed, or if there was something more in it that allowed it to succeed.The first difference is the protocol : similar to ABC/HR in the one that failed, but without ranking the samples, just telling if they are different, and an A-B-A playback followed by a binary quality evaluation in the one that succeeded (soft/hard, balanced / unbalanced etc).The duration might have been different. In the sucessful test, the samples were always played during 30 seconds. It is not mentionned in the other test.The material was different too. I'd like to perform a spectrum analysis of a raw gamelan recording (the instrument recorded in the test that succeeded, and that was not present in the one that failed), but with a short analysis window. The overall analysis doesn't show any special high frequency content that would be missing in the other test, but since the gamelan is a percussive instrument (on metal), I wonder if it is possible for the high frequency content to be concentrated during the attacks only. This way, it would be very powerful at some given times, but the average power on the whole sample would not represent faithfully the instant HF level that is present during the attacks. If it is the case, drawing a spectrogram with shorter analysis windows would show shorter but more powerful HF bursts, as long as the bursts are shorter than the window itself.I tried with the only CD I have featuring Gamelan (Akira soundtrack, track 4 - Tetsuo), but it didn't show such a behaviour. However, this movie soundtrack is heavily processed, and the Gamelan sound might have been tampered with.We could say also that a 10 ms analysis window (4096 samples in 44100 Hz) represents best the human hearing, but I don't think that it is a valid argument. Since we study the hypothesis of inaudible sounds possibly intermodulating in the audible range, the process is necessarily nonlinear, and the relevance of this 10 ms window might not stand in these conditions.