Subject: Re: MH Acoustics: Eigenmike From: Elena Grassi <elena.grassi@xxxxxxxx> Date: Fri, 13 Jul 2007 09:49:48 -0400 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>------=_Part_22800_33265670.1184334588203 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline I think the spherical mike is a good idea to record 3D sound fields, but perhaps one important question to ask is what is the bandwidth of the signal that you can beamform without aliasing. As you move up in frequency I think you need a high resolution (comparable to the size of the wavelength that you are trying to discriminate) on the surface of the sphere to avoid aliasing in your beamform. Conversely, if you make your sphere small to achieve a high resolution with a few microphone elements, then you are missing the directionality in the low frequency. So, there is a trade off between size of the sphere and number of microphones needed. Perhaps they partly solve the problem by having a nonuniform density on the sphere? This is an interesting topic. I'd like to hear what others have to say... All the best, -elena ---------------------------------------------------------------------- > > Date: Thu, 12 Jul 2007 13:43:26 -0400 > From: Tony Miller <antonio.miller@xxxxxxxx> > Subject: MH Acoustics: Eigenmike > > ------=_Part_24546_30308866.1184262206643 > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > Content-Transfer-Encoding: 7bit > Content-Disposition: inline > > Listmembers- > > I am curious to know if anyone in the binaural hearing research community > has ever used the MH Acoustics Eigenmike for an experiment. It seems like > it would be infinitely useful for recreating accurate 3D sound fields, yet > I > have never seen a publication referencing it's use. Am I not looking in > the > right place, or has it simply not been adopted as a standard tool yet? > > http://www.mhacoustics.com/page/page/2949006.htm > > Any insight is appreciated. > > Thanks. > -Tony > > -- > Tony Miller > Motorola APTC Acoustic Technology Center > 8000 West Sunrise Blvd, Mail Stop 22-7-F > Plantation, FL 33322-4104 > Cell: (954) 605-7982 | Desk: (954) 723-3989 > > ------=_Part_22800_33265670.1184334588203 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline <p>I think the spherical mike is a good idea to record 3D sound fields, but perhaps one important question to ask is <br>what is the bandwidth of the signal that you can beamform without aliasing. As you <br>move up in frequency I think you need a high resolution (comparable to the size of the wavelength <br>that you are trying to discriminate) on the surface of the sphere to avoid aliasing in your beamform.</p> <div>Conversely, if you make your sphere small to achieve a high resolution with a few microphone elements, <br>then you are missing the directionality in the low frequency. So, there is a trade off between size of <br>the sphere and number of microphones needed. </div> <div> </div> <div>Perhaps they partly solve the problem by having a nonuniform density on the sphere?</div> <div> </div> <div>This is an interesting topic. I'd like to hear what others have to say...</div> <div> </div> <div>All the best,</div> <div> </div> <div>-elena</div> <div> </div><br><br> <div> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">----------------------------------------------------------------------<br><br>Date: Thu, 12 Jul 2007 13:43:26 -0400 <br>From: Tony Miller <<a href="mailto:antonio.miller@xxxxxxxx">antonio.miller@xxxxxxxx</a>><br>Subject: MH Acoustics: Eigenmike<br><br>------=_Part_24546_30308866.1184262206643<br>Content-Type: text/plain; charset=ISO-8859-1; format=flowed <br>Content-Transfer-Encoding: 7bit<br>Content-Disposition: inline<br><br>Listmembers-<br><br>I am curious to know if anyone in the binaural hearing research community<br>has ever used the MH Acoustics Eigenmike for an experiment. It seems like <br>it would be infinitely useful for recreating accurate 3D sound fields, yet I<br>have never seen a publication referencing it's use. Am I not looking in the<br>right place, or has it simply not been adopted as a standard tool yet? <br><br><a href="http://www.mhacoustics.com/page/page/2949006.htm">http://www.mhacoustics.com/page/page/2949006.htm</a><br><br>Any insight is appreciated.<br><br>Thanks.<br>-Tony<br><br>--<br>Tony Miller<br>Motorola APTC Acoustic Technology Center <br>8000 West Sunrise Blvd, Mail Stop 22-7-F<br>Plantation, FL 33322-4104<br>Cell: (954) 605-7982 | Desk: (954) 723-3989<br><br></blockquote></div> ------=_Part_22800_33265670.1184334588203--