In the past couple of years I’ve noticed more field recordists have been experimenting with recording ultrasonic frequencies.
For those new to the idea, ultrasonic sounds are those beyond the scope of our hearing: 20 Hz to 20,000 Hz.
Normally, those frequencies would be out of reach to recording fans. Why? Well, not only are those frequencies beyond the capacity of our ears, they are out of reach for most equipment to capture at all. Most microphones are designed to capture only the scope of our hearing: 20 Hz to 20,000 Hz. However, some elite microphones reach farther into the ultrasonic spectrum, capturing frequencies as high as 100,000 Hz! When such a microphone is paired with recording at high sampling rates, sounds beyond our hearing can be recorded.
Why bother recording sounds you can’t hear? Well, with high sampling rates and ultrasonic content, sound designers are able to pitch the audio down and have interesting sounds to play with.
Recently, a community field recordist experimented with recording ultrasonic sounds in a novel set-up.
Ultrasonic Parabolic Field Recordings
Last month field recordist Michal Fojcik experimented with recording ultrasonic sounds with an unusual kit: a parabolic dish. He used a Sanken CO-100k and a Telinga dish to record wildlife ranging from frogs to birds to crickets.
In an article on his Sound Mind blog, Fojcik describes how he mounted the Sanken. He shares recordings of both it and the stock Telinga mic. What is particularly interesting are the iZotope RX spectrum snapshots he posts, which give a very clear picture of how much sonic content is beyond the scope of our hearing.
Check out Ultrasonic / Parabolic Experiments on the Sound Mind blog.