What's the problem with double-blind testing? Options

[mirrorsawlljk]

I happened to pick up an issue of stereophile at a record store I visited and I was pretty shocked to see a seemingly intelligent person in the correspondence section bashing double blind testing as being unreliable. I'm afraid I don't understand his angle of attack. I don't see how anything could be a more reliable test of sound quality differences than a properly conducted double blind listening test.

I'm almost afraid to read the rest of the magazine if this is the kind of letter they think is worth publishing. Is there an audio magazine that isn't filled with this kind of thinking?

[KikeG]

The "goosebump", emotional factor can be caused by placebo effect, you can't be sure that is not the cause. People has used same principle (emotional response and the like) to say cables sound different, for example.

You can do long-term blind tests too, not just the quick-switch, short snippet, typical abx test.

This post has been edited by KikeG: Oct 19 2005, 11:55

[Donunus]

The "goosebump", emotional factor can be caused by placebo effect, you can't be sure that is not the cause. People has used same principle (emotional response and the like) to say cables sound different, for example.

You can do long-term blind tests too, not just the quick-switch, short snippet, typical abx test.

What do you mean by long term abx? how do I do this? Play entire songs? actually can you give me a link that explains placebo. thx

[kjoonlee]

actually can you give me a link that explains placebo. thx

The word placebo, when used in audio circles, is a little different from the medical term, where people can actually benefit a little from dummy treatments.

According to ff123, it's closer to expectation bias, where a person's expectation can influence his perception, if I understand correctly.

[Woodinville]

actually can you give me a link that explains placebo. thx

The word placebo, when used in audio circles, is a little different from the medical term, where people can actually benefit a little from dummy treatments.

According to ff123, it's closer to expectation bias, where a person's expectation can influence his perception, if I understand correctly.

While I don't disagree, I'd go farther.

If you look at what the auditory system detects as an "event", it appears from the work done to be set to detect many 'false events' at a much lower risk of missing a real event.

This kind of performance (tradeoff between misses and false detections) is obligatory for any probabilistic system, of which the auditory system is quite.

I have heard this explained to others (somebody said this at a tutorial at the NY aes, for instance) as being for a simple reason:

If you hear the tiger coming, and hide, you live.

If you don't hear the tiger coming, you are out of the gene pool.

If you hear the tiger coming, and it isn't, all you do is look a bit silly.

If you consider that we are wired to detect nonevents in favor of missing any events, then that would explain quite nicely why changes cause "differences".

[duff]

If you consider that we are wired to detect nonevents in favor of missing any events, then that would explain quite nicely why changes cause "differences".

One has to be careful about generalizing this principle across all domains. Signal detection applies to many perceptual phenomena, but the costs and benefits associated with the four possible outcomes (hit, miss, false alarm, correct rejection) vary depending on what you are attempting to detect. So we aren't wired to detect "non-events" over events in general. For predator detection, yes...but not for something like, for example, detecting cheaters in a card game!

[Woodinville]

So we aren't wired to detect "non-events" over events in general. For predator detection, yes...but not for something like, for example, detecting cheaters in a card game!

Really, now, would you like to show your evidence?

The evidence that partial loudness differences are overdetected has been in for years.

All auditory stimulii start out as a set of partial loudnesses, as expressed as pulse position modulation in the auditory nerves.

If you're right, this would require a complete revision of the entire understanding of how the human auditory system works. Have you this revision prepared yet?

This post has been edited by Woodinville: Oct 21 2005, 21:15