Subject: Re: making a sound unrecognizable (the satanic trick) From: Brian Gygi <bgygi@xxxxxxxx> Date: Wed, 13 Sep 2006 05:21:23 -0700Hi Massimo Actually, I did a study on identifiability of time reversed sounds (presented at the 2004 ARO) in which I found that time reversal was only good at obscuring very short sounds, such as an axe chopping. Longer sounds, such as a tree falling and baby crying were barely affected at all. I think that longer sounds are more robust because of the the long term spectral structure. Most shorter sounds have broad band spectra so the only cues available are temporal. Best Brian On Wed, 13 Sep 2006, Massimo Grassi wrote: > > a good way to make a sound unrecognisable is to play it backward in > time (see for example, the ASA demo cd). Acoustics parameters are > untouched (although time reversed). It might not work for amplitude > steady sounds (e.g. a food blender). > > Ciao, > m > ******************** > Massimo Grassi - PhD > Laboratorio di Psicologia > Via Petracco 8 - 33100 Udine - Italy > http://www.psy.unipd.it/~grassi > IMPORTANT! BEFORE SENDING REGULAR > MAIL PLEASE SEND AN EMAIL > > ---------------------------------------------------------------------- > SEMEL (SErvizio di Messaging ELettronico) - CSIT -Universita' di Udine > >