Greetings to All,
I have been reviewing the literature on Auralization in attempts to create
viable stimuli for research. Everybody here has been great. I do have another
question/comment regarding loudspeaker placement.
In nearly all Ambisonic setups, the listener's head lies on a line connecting
two or more speakers. This includes the 4-speaker cube arrangement. I've noted
that having two speakers immediately to the left and right of the head creates
an image that's similar to headphone listening; in other words, it's akin to
lateralization versus localization effects. Is there any reason not to use an
odd number of speakers arranged in such a way that no two speakers form an
imaginary line passing through the listener's head? I am considering building a
hybrid system based on Ambisonics and Ambiophonics, and was considering a
pentagonal loudspeaker arrangement. The "Ambiophonic" component would be using
dividers (gobos or flats, as they're called) between speakers so as to reduce
early reflections in an otherwise "standard" living room space. From what I've
read about Ambiophonics, it's an extension of transaural stereo techniques
(e.g. William Gardner's doctoral
thesis) with the addition of a partition. It seems that the advantages
provided by the partition (or partitions in my case) would apply to Ambisonics.
Please bear in mind that I am designing a system for single-listener research,
so the obvious disadvantages of dividers (i.e. space hogs) isn't an issue. Has
anyone had experience using dividers?
I've also been creating research stimuli using avatars (for lipreading), AT&T
Natural Voice text-to-speech (ATT Labs makes high res voices) software for
creating sentences, and IRs recorded with a SoundField mic. Daniel Courville's
website and Bruce Wiggins WigWare are fantastic resources for any of us
attempting sound design via Ambisonics. I also have a licensed (meaning
paid-for) version of Harpex, and this is highly recommended for those who can
afford it. One of my favorite post production DAWs is Sony Sound Forge 10. I'm
often having to convert numbers of channels (e.g., four B-format channels to 8
processed channels), and this is very easy to do with Sound Forge. I also use
digidesign Pro Tools and Steinberg Nuendo, but neither of these is as easy to
use as Sound Forge.
For the home brew crowd out there, I'll probably upload my plans for a
multi-channel preamp based on Burr Brown chips. The impetus for building such a
device (versus buying a ready-made surround sound controller/preamp) is that I
can use software to control the gain on the Burr Brown chips (a rotary
controlled encoder is used for conventional volume control). I'm devising
experiments where the signal-to-noise ratio has to vary depending on a
subject's response (e.g., two "misses" in a row means increase the SNR). The
software controller does this automatically, and a MIDI track on a DAW can be
used to track the changes. Just passing this along for other researchers...
Disclaimer: Suggestions, questions, and ideas presented herein are in no way a
reflection of my cat, who is far wiser than yours truly.
Eric
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<https://mail.music.vt.edu/mailman/private/sursound/attachments/20121003/b2a838f7/attachment.html>
_______________________________________________
Sursound mailing list
[email protected]
https://mail.music.vt.edu/mailman/listinfo/sursound
