occam;190702 Wrote: > Given the brevity of aural memeory, (borrowing the phrase from Sean) > I'll bet dollars to donuts, that few of you have conducted a valid > hardware DBT audio test. 30+ yrs ago, I did nothing but set up the > switching mechanisms for (admittedly non audio) tests at Hopkins > Medical School and the Maryland Psychiatric Research Center. Whatever > anecdotal results have been discussed here wouldn't pass peer journal > review criteria of those days, let alone whatever minimal criteria are > acceptable today. > Its straightforward to set up valid SBT or ABx tests, iff you have > circuit level access, and you're dealing with a situation where > (generally) nothing is turned off, levels matched and interruptions of > sound <5 seconds. This is why the Good Lord, in Her infinite wisdom, > has given us 4pdt switches, if you're dealing with something as > straightforward as power conditioning. And its not that incrementally > difficult to extend those tests to DBT with a computer and sufficient > quality relays. But other areas.... good luck. Leastwise, this is what > my students, 1 month away from recieving their BSEEs are finding out in > their senior lab course. Its actually more comical to watch them > breadboard and solder a simple circuit. > > > > I've banned discussions about DBT in the Lab Circle at AudioCirle, not > discussion of actual DBT tests. I'm a strong believer in valid testing. > Its appears that folks find it far prefferable to invoke the shibboleth > of DBT rather than actually perform a valid one. Personally, I find > such discussions 'about' a boring, repetitive, fruitless exercise in > Onnanism. But if talking about it, rather than actually doing a valid > experiment, floats your boat, enjoy.
Amen. As far as valid experiments in audio, there aren't any that I know about. Note that even in an ABX test, there should probably be positive control groups to insure that sensory thresholds are not shifting as a result of the procedure. However, it's worth considering the brevity of auditory memory. Consider a thought experiment. Your phone rings, and a voice says "Hello". You identify your significant other and respond appropriately. Note that this is completely blind, and in the absence of identification, the only stimuli are auditory. However, I'll bet that you can identify your SO's voice significantly better than chance, even with a degraded signal over a phone line. If not, you'll be in trouble at home. So, there are some aspects of auditory memory that last a lot longer than the couple of seconds people credit to it. Inflection, tone, parsing etc. etc. are all aspects of an auditory event that can be remembered, and it's pretty clear that some are remembered better than others. So, I'm not entirely sure that we can take the brevity of auditory memory as a given. Perhaps memory of pitch (although people with perfect pitch might well remember for extended periods)...but at least some aspect of an auditory signal allows us to identify people on the phone even if we haven't heard their voice for extended periods (months, rather than seconds). If it's not memory, then what is it? -- hirsch ------------------------------------------------------------------------ hirsch's Profile: http://forums.slimdevices.com/member.php?userid=7288 View this thread: http://forums.slimdevices.com/showthread.php?t=33547 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
