Correction to my last post. It should have read...
...even if the limit of human temporal resolution is *two hundred* times higher than Kunchur claims, that would still place it at only 1ms, in which case placement differences of approximately a foot or more would result in potentially audible time misalignment.
AND...
What I can say is that, IME, differences in z-axis sub placement are audible down to about 4 inches. That would correspond to about *300µs*.
I was off by an order of magnitude. D'oh! I should not do math in my head at midnight.
In any case, my error actually *underestimated* the degree to which Kunchur's estimate could be off while still making time misalignments of about a foot potentially audible, leaving my argument for the importance of subwoofer time alignment unaffected.
04-20-11: Dbphd
I wondered why someone from a university in South Carolina would publish such an article in other than JASA.
It's true that Kunchur's article wasn't published in JASA, but here is a list of articles that WERE, all on the subject of human temporal resolution:
--B. Leshowitz, Measurement of the two-click threshold, J. Acoust. Soc. Am. 49, 462466 (1971).
---Ronken, D. (1970). Monaural detection of a phase difference between clicks, J. Acoust. Soc. Am. 70, 10911099.
--Henning, G. B., and Gaskell, H. (1981). Monaural phase
sensitivity with Ronkens paradigm, J. Acoust. Soc. Am.
70, 16691673.
--Plomp, R. (1964). Rate of decay of auditory sensation, J. Acoust. Soc. Am. 36, 277282.
--Penner, M. J. (1977). Detection of temporal gaps in noise as a measure of the decay of auditory sensation, J. Acoust. Soc. Am. 61, 552557.
--Eddins, D. A., Hall, J. W., and Grose, J. H. (1992). Detec- tion of temporal gaps as a function of frequency region and absolute bandwidth, J. Acoust. Soc. Am. 91, 10691077.
And here is Kunchur's synopsis of the conclusions of those JASA articles...
In one experiment by Leshowitz (1971), listeners were presented with a single pulse or two narrower pulses (with the same total energy) separated by an interval Δt. The click and click-pair could be distinguished down to Δt ≈ 10 μs. In this case, the two stimuli have differences in their amplitude spectra and their discernment was explained on this basis. Isospectral variants of this experiment were carried out by Ronken (1970) and later by Henning and Gaskell (1981) where one stimulus consisted of a short pulse followed by a taller one separated by an interval Δt. The second stimulus was a similar pair with the time order reversed and hence had the same amplitude spectrum. The shortest Δt for which these stimuli could be distinguished was about 200 μs. Another type of constant-amplitude-spectrum experiment involves the detection of gaps in noise (Plomp, 1964; Penner, 1977; Eddins et al., 1992). In these the threshold for gap detection was of the order of 2 ms.
As you can see, those estimates of the limits of human temporal resolution range from 2ms to 200μs all the way down to 10 μs. If we average those estimates, we get 736μs, which corresponds to differences of less than a foot.
Hence there is reason to believe that the human limits of temporal resolution may be sensitive enough to make time misalignments of a foot or less potentially audible.
Bryon
Bryon
