This is the sort of “3D” that I will not up with put!

3DRemember the opening sequence Sesame Street? Well, this post is brought to you by the number 3 and the letter D…cuz some of you weren’t paying attention all those years ago!

Both Voxeet and Dolby Voice are interesting binaural conference services. However, some of the marketecture being deployed sets off alarm bells in my mind. Despite claims to the contrary, and the echo of such claims by the media, I don’t believe that what they offer is “3D audio.”

I accept that this may just be a matter of semantics. To those who have a passionate interest in truly immersive surround sound the term “3D” has significance. It’s abuse diminishes its meaning.

To be truly 3D means conveying information relating to the X, Y & Z axes. As far as I can tell neither of those services engage the Y axis, where height information is presented.

English mathematician Michael Gerzon, creator of the Ambisonic approach to surround sound, coined the term “Periphonic” to describe an audio system capable of the conveyance of height. Only a few of the most elaborate surround sound systems even attempt to convey height in a meaningful way.

There are researchers working on approaches to the practical delivery of bone fide 3D audio. Such efforts tend to focus on soundscapes for art installations, theme parks or movies. NHK has proposed a 22.2 channel surround sound standard for UHDTV & SUHDTV that has periphonic capability.

There’s a surround sound mailing list based at Virginia Tech that’s a great resource if such matters are of interest to you. It’s loaded with academics, musicians, composers and engineers who have experience from the present day going all the way back to the days of quadriphonics.

On a smaller and more practical scale, Hugh Pyle documented a neat project where he used a handful of small speakers and some pipe to build a portable Ambisonic playback cube. His is a simple cubic array is truly capable of 3D playback for one person. It’s genuinely neat stuff!

The sort of business communications targeted by Dolby Voice and Voxeet don’t actually require that height be conveyed so this is just a matter of linguistics. These services can rightfully be known as “binaural”,  “stereo” or even “immersive” conferencing. Those terms just don’t have the heft and emotional resonance of “3D Audio.”