Subject: Re: About importance of "phase" in sound recognition From: James Johnston <James.Johnston@xxxxxxxx> Date: Fri, 8 Oct 2010 12:46:34 -0700 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Whoa. I just drifted off there. 500Hz at 1, .25 at 500-4 and 500+4 Or you can use 1khz and then use 1000+4 and 1000-4. I believe I suffered a change of center frequency between the first and second parts of my post. Sorry. __________________________ James D. Johnston (jj@xxxxxxxx) CHIEF SCIENTIST - DTS, Inc. 425-814-3200, ext. 134 - office 425-814-3204 - fax 206-321-7449- mobile 11410 NE 122nd Way, Suite 100 Kirkland, WA 98034 This electronic transmission (and/or the documents accompanying it) may contain confidential and privileged information. Any unauthorized use, copying or distribution is prohibited. If you have received this communication in error, please notify DTS, Inc immediately by telephone (425-814-3200) and destroy the original message. Messages sent to and from us may be monitored. -----Original Message----- From: AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxx On Behalf Of Joachim Thiemann Sent: Friday, October 08, 2010 8:35 AM To: AUDITORY@xxxxxxxx Subject: Re: [AUDITORY] About importance of "phase" in sound recognition On Fri, Oct 8, 2010 at 09:33, emad burke <emad.burke@xxxxxxxx> wrote: > By the way, I apologize for not providing the reference for the mathematical > article that I referred to in the previous email. here is a link to it : > > http://www.math.missouri.edu/~pete/pdf/132-painless.pdf > Hello Emad, from my quick reading of this paper (since the topic is quite interesting to me) I notice the following (others feel free to correct me if I get this wrong): - to reconstruct a N-dimensional (complex) vector from magnitude only coefficients you need N^2 coefficients (N(N+1)/2 for real vectors). An earlier paper (in SPIE 2007) talks about sparse representations needing as little as 2N-1 coefficients (in the real case). I am not certain yet if they have generalized it to the complex case, and it this only applies to a specific set of frames. - reconstruction from magnitude only will always be within a root of unity (that is, the solution will be a set of vectors that differ from each other by e^{-i\phi} \phi=0...2\pi as one expects. Thanks for the link though! I am still working in reconstruction from the basis of Griffin&Lim's iterative reconstruction algorithm, so this is quite interesting to me. Joe. -- Joachim Thiemann :: http://www.tsp.ece.mcgill.ca/~jthiem Notice: This message and any included attachments are intended only for the use of the addressee, and may contain information that is privileged or confidential. If you are not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please destroy the original message and any copies or printouts hereof.