Re: Pre-echo audibility AND backward masking (Bill Budd )

Subject: Re: Pre-echo audibility AND backward masking
From:    Bill Budd  <bill(at)PSY.UWA.EDU.AU>
Date:    Mon, 6 Jan 1997 19:15:43 +0800

Dear Soren Thanks for your response. I am a doctoral student and interested in phenomena associated with the temporal delay between auditory stimuli, primarily in relation to brain electrical activity (ERPs). I'm not familiar with echo studies but this is obviously interesting for me. In regard to pre-echo audibility, I wonder if loudness enhancement might not play a role here. That is, detection thresholds for the first sound may be lower BUT only relative to the threshold for the second sound, which is higher due to loudness enhancement? There are a couple of papers describing loudness enhancement if you think it's relevant: Zwislocki et al 1974 Percept. Psychophys 16: 87-90;& 91-95. Zwislocki et al 1959 J. Acoustic. Soc. Am. 34 9-14. Efron is another author who has done some relevant work. Loudness enhancement is often interpreted in terms of the temporal summation of acoustic energy of two closely spaced the brain not the ear. This is what I'm interested in in relation to backward recognition masking "BRM".... which is different from backward detection masking "BDM" in that subjects are asked to make a judgment about the the pitch or intensity of the probe not simply detecting it as is the case for BDM. This may then be relevant to your original question as although BRM experiments typically use a masking tone that is physically different from the probe as is the case in BDM (usually longer duration only), I have found (and maybe others as well) that BRM paradigms can produce masking when the probe and mask are identical. Essentially I'm wondering whether BRM effects may be relevant to the echo phenomenon as well. There are some good reviews of theoretical an empirical information relevant to BRM and BDM which relate to processes such as temporal summation, auditory persistence, echoic memory etc. from authors like Nelson Cowan, Dominic Massaro which may be interesting to you. I would appreciate any references or information you have (or any list members) that discuss physical similarity between the probe and mask and how this relates to probe detection (or recognition) thresholds. Regards Bill At 08:55 AM 6/01/97 +0100, you wrote: >Dear Bill, > >Thanks for your mail. > >I'm sure you are familiar with usual Post-echo where a sound is followed by a >delayed and attenuated copy of itself. This happens, for instance, if you shout > >in a long corridor. > >Pre-echo is the opposite phenomena where the first occurence of the sound is >weaker than the delayed. This does not happen in natural "passive" surroundings > >but can be created electronically. I think the effect was first noted as >pre-print-through on magnetic audio tapes that had been stored on the wrong >reel. > >Please get back to me if you have any information on the audibility of such >pre-echoes. > >Regards, > >Soren Laugesen >Oticon A/S >Research Centre, Eriksholm >DK-3070 Snekkersten >DENMARK > > _______________________________________________________ Bill Budd Cognitive Neuroscience Laboratory, Department of Psychology, University of Western Australia, \ ? / Nedlands. 6009. | Phone: 09 380 3468 Fax: 09 380 1006 Email: bill(at) _______________________________________________________

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