opaqueice;177833 Wrote: > But blind testing is actually a lot more useful than a voltmeter, > because it tells us what we really want to know - whether we can hear a > difference. In your rather perfect example, blind testing would be a > very natural thing to discuss - one would want to ask, is that change > in the frequency response audible?
Here is the main logic error in DBT. DBT does not prove anything exists. It's simply a control condition to enable the interpretation of positive results when a difference is found. You have a difference. You don't know if the difference is due to physical or psychological influences. DBT can help rule out psychological influence. You've run DBT. Congratulations! Your difference is likely not due to psychological influence. If you hear a difference, and can go back and measure a difference in the stimuli, why bother with DBT? It's not a necessary control at that point. You've got a measurable difference, and you can hear it. Done. The other main problem with DBT is the misinterpretation of negative results. The absence of a positive finding with DBT does not imply a negative result. It simply indicates that no difference was found in that test situation. So what? People look at random results in a DBT, and suggest that there is no difference in the stimuli. However, psychological factors work both ways, and can mask real differences as well as producing artifical ones. What steps were taken to insure that the negative result is real? Here's a question that you need to ask in interpreting DBT: Is there anything in these results that are different than those that would be produced by a person with hearing loss? Bear in mind that a random result could be produced by someone with profound hearing loss, even when a large audible difference is present. So, in any given test, we've got to ask what steps were taken to insure that small audible difference are accurately detected as a bare minimum before taking any negative DBT results seriously. Were positive control groups, with known audible differences, part of any DBT experiment? Without them, a negative DBT is meaningless. As long as DBT is used properly, as a control condition to aid the interpretation of positive results, it's an important and useful test. However, general misunderstanding of its limitations, by proponents and opponents of DBT, as evidenced by the quote above, has made it fairly useless as a tool in audio. The debate is much ado about nothing. DBT can help interpret an apparent positive difference. That's it. No application to negative results whatsoever. -- hirsch ------------------------------------------------------------------------ hirsch's Profile: http://forums.slimdevices.com/member.php?userid=7288 View this thread: http://forums.slimdevices.com/showthread.php?t=32352 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
