Binaural Audio

Yesterday was the first day of the Capitol AudioFest here in Washington DC. Gary Gill has put on a small but well-organized show for four years in the DC area and this is my second year participating and presenting. I hauled two 50-pound hard shell Samsonite suitcases loaded with playback equipment (an Oppo BDP-95, a Smyth Room Realiser, Benchmark DAC1, video monitor and a couple pairs of headphones) and AIX Records products (DVDs and Blu-rays) from the west coast to a sales table on the fourth floor this year. The Magnolia Room is also populated by other vendors hoping to interest attendees with their products. It’s an interesting bunch, there’s Bob (from Bob’s Devices) who offers step up transformers for moving coil cartridges, Misha from Mytek and his amazing DACs, a couple of guys selling home automation equipment and Chris (from Cash for Music.com), my neighbor in the middle of the room, offering bin after bin of vinyl LPs.

Chris has a large wire frame display that features a number of his albums. It happens to be open on the back and I noticed a Lou Reed album called “Take No Prisoners” that had the designation “binaural” printed on the back (Lou Reed actually released 3 binaural recordings). I asked Chris if he knew anything about the record and he responded that he didn’t. In fact, he didn’t realize it was recorded using a binaural head. He admitted that he didn’t even know what binaural means. I thought today would be a good time to introduce “Fritz” to him and to the readers of this post.

Binaural recordings are done using a “dummy” head. Neumann, a very well known German maker of high quality microphones makes one affectionately known as “Fritz”. The official model number is the KU-81 or the updated model the KU-100. It comes in silver metal container about the size of a human head because it is solid rubber stylized human head with well articulated soft rubber pinna (or outer ears) and high quality microphones inside the head where eardrums would normally be.

The concept is that a recording made using microphones located inside a physical head with real looking ears will result in a recording that sounds 3-dimensional. And it works as long as you listen back to a binaural recording through a set of headphones. Whatever Fritz’s heard through his left ear has to be delivered to the listener’s left ear and the likewise for the right. Binaural recordings don’t work through loudspeakers (although Chesky claims that he has collaborated with a researcher at Princeton to perfect binaural through speakers…I’ve heard it and it didn’t work for me).

In the mid 80s I recorded a bunch of source material for my dissertation composition using a Fritz binaural head and my stereo Nagra IV-S portable analog tape machine. The concept for the piece was transmigration or the journey from one spiritual or physical place to another. The piece used subterranean sounds, ground level sounds and ultimately sounds recorded from a hot air balloon ride. Fritz and I spent a lovely week together running around California trying to find interesting sound environments. I’ll share some of those source recordings when I get back to Los Angeles.

That Lou Reed would use this technology for a commercial record release was compelling and highly unusual. Chris pulled it out and walked over to Bob’s area and played it through a great set of phones to get the full effect. Both Bob and Chris reported back that it was somewhat disturbing to have Lou speaking to them that close to their ears…kinda creepy was the general sentiment. And besides Bob never liked Lou in plain old stereo!