tim's journal

Handheld sound studio

I looked into binaural recording several years ago prior to my trip to Russia. The topic recently resurfaced as Sonja and I were looking for a CD with ocean sounds. Fanatasies of a binaural recording of the ocean immediately popped into my head. After some distraction, I have concluded that Len Moscowitz's Core Sound is the way to go.

Mr. Moscowitz is a graduate of Rutgers, Polytechnic Institute of New York and The City University of New York. Holding degrees in electrical engineering and psychology, he spent more than 20 years working on artificial intelligence, waveform analysis and radar jamming for the US Aerospace industry. He also plays bass guitar and guitar, and enjoys recording and composing. So, the background is good.

Core Sound specializes in high quality stealth recording. Think U2 concerts... Of course, they recommend asking for permission before recording. People also use their systems to record ambient sound, such as the ocean. Their high end binaural (HEB) microphones are a bit rich for my blood (~$900), though about an order of magnitude less than professional gear such as the Neumann KU-100 dummy head (~$8000). The HEB set utilizes a set of DPA4060 microphones from Bruel & Kjaer, which Moscowitz claims as "the very best binaural microphones available anywhere".

So how does this work? The microphones are clipped to glasses, a helmet, your belt, or under your collar, seperated by a head's width. In the ideal (and more expensive) world, the microphones are inserted into the ear to truly capture the sound, including the transfer function coming from the ridges and valleys of the ear. On top of the microphones, you will need a dat recorder, an md recorder, or a way of amplifying and digitizing the audio into a digital device such as a PDA or a laptop. Core Sound sells a package to do the latter. Audio is captured and digitized using PDAudio, which consists of a Mic2496 dual microphone pre-amp and A-to-D converter ($499), a S/PDIF to Compact Flash adapter ($199), optical cabling ($15), "Live2496 software" ($50), and, if you don't have it, a PDA/laptop with associated memory. To be portable, you will probably want a PDA ($300) and a lot of memory ($250-300). You can see this is becoming an expensive endeavor.

For the hobbyist (CD-quality), it may be sufficient to purchase Core Sound's original microphones ($260). Though not as sleek and small, for 16-bit/44.1 kHz recordings, it may well be sufficient. The HEB 4060 is really designed for 24-bit/96 kHz recordings, so-called DVD quality. The microphones can then be plugged into an old MD or DAT recorder. While the sound quality may not be as high, I suspect it will probably be sufficient. The main issue with using a mechanical device is that noise is injected into the recording. A solid-state memory such as Compact Flash or SD can avoid this.