The Mannequin Head
The first thing you will need is a mannequin head. There are many sources for mannequins on-line, but there are some design criteria that you should keep in mind.
- Size- The size of the head should be as close to that of a human head as possible. The reason for this is that there will be time delays between sounds arriving at one ear versus the other. If your dummy-head is the same size as a human head, these time delays will be correct in your recordings.
- Material- This tutorial will use a hollow plastic head, simply because it allows easy access to the inside for assembly. Styrofoam heads would make mounting of the ears difficult. Plus, a hollow head allows you freedom to fill the inside with any type of material.
- Ears- Some mannequin heads have existing ears. If you're looking at a mannequin head that already has ears on it, make sure they're located in the same place as where your binaural ears will be located (see tutorial section about ear mounting). This makes for a cleaner process. For mannequin heads with existing ears, we will cut these ears out further on in this tutorial. If the existing ears are in a strange location, you might have to do some creative destruction...
- Orientation- Some mannequins are in a strange pose or orientation. For the most natural results in your recordings, you'll want to get a head that is basically straight up and down, looking forward with no tilting of the head.
- Shoulders or Torso- The human shoulders and torso add to the effect of our sound localization. Some binaural folks believe that it is worth the effort to include these in their dummy-head design. I have done this with one of my dummy-heads. To be honest, It's hard for me to say whether the localiation is better or worse. I will leave it up to you to decide if it's worth the $$ to get a more complete mannequin base to start from.
I've found that Roxy Display has a good source of heads for a good price. The head I prefer to use (model MD-EraW2 shown on the left) can be found here. Roxy also has full torso (or even full body) mannequins if you want to go that route.
