Jar Fly Blues
"Again and again, the cicada's untiring cry pierced the sultry summer air like a needle at work on thick cotton cloth."
Recording location audio outside can be challenging at best. The video team wants an exterior shot because architecture or a landscape in the background can add to the image. But alas, there are often unwanted sounds like cars, HVAC blowers, and other manmade annoyances that we must work around. There's one sound though that is nearly impossible to eliminate, fix, mask, hide, or yell-at-to-be-quiet. It is guaranteed to ruin almost any exterior recording in the summer: the mating song of the cicada.
These little bug(ger)s come out of the ground periodically (mostly every 13 or 17 years here in the Ohio Valley) to anchor themselves to a tree and incessantly cry out for all to hear. It's not their little vocal chords that are producing these 120-decibel cries. The jar flies are contorting their torsos to flex in and out, causing two tymbals, or ribbed membranes, to vibrate 300-400 times a second. This produces a noise that's as loud as a jet engine and between 3KHz and 16KHz - right smack in the middle of the human speech range.
Human speech generally falls between 3KHz to 5KHz, like the sound of an old-time phone call. The nuances of intelligibility, such as the consonants S, H, F, and so on, are heard above 5 KHz. That makes removing the background sounds of cicadas difficult because you could also remove subtle sounds of speech. Noise reduction software has become very sophisticated today, but dynamic sounds like cicadas (their cry rises and falls in pitch and loudness instead of being drone-like) poses many challenges. We can painstakingly "paint out" some of the offending sounds, but it's best to leave some of it in so we don't lose key frequencies in the voice. If a dialog track with cicadas is heavily edited, then this can result in having cicadas in one clip and not the next. Or falling in one clip and rising in the next. This is jarring to the listener and is very difficult to fix. We sometimes actually add cicada song back in underneath to mask those continuity-challenged edits.
While recording, we can sometimes position the microphone and talent to reduce the cicada song, but inevitably a critter in another tree fires up his belly to blow the take. There's just no easy solution to this dog day dilemma. The sound is so hated, Japanese television has a Godzilla-like monster called "Cicada Man," probably created by a sound engineer. They're so passionately tired of them in Mexico that Raymundo Pérez y Soto penned the great mariachi song "La Cigarra."
But leave it to the U.S. Navy to find the positives in the piercing cicada death song. The Navy is no stranger to harnessing wildlife to help their efforts. They have a marine mammal program that uses bottlenose dolphins and sea lions for mine detection, ship and harbor protection, and equipment recovery. What on earth could they use a cicada for?
The Naval Undersea Warfare Center in Rhode Island has been studying this tiny creature's anatomy with a CT scan-like technology called microcomputed tomography to try and figure out how it makes its loud chirp. They've found that a cicada's two tymbals act as dual speakers when the insect contracts and releases their ribs. It's a highly efficient way of producing twice the sound with one action. And why would the Navy be interested in sound? Why sonar of course. Doubling sonar's efficiency is like seeing twice as far with radar.
It seems that Raymundo Pérez y Soto was ahead of his time in the 1950s when he wrote La Cigarra. He may have foretold the odd marriage of the cicada and the Navy:
Don’t sing to me anymore, cicada
Let your singsong end
For your song here in my soul
Stabs me like a dagger
Knowing that when you sing
You are announcing that you are going to your death.
Tell me if it is true that you know,
Because I cannot distinguish,
Whether in the depths of the seas
There is another color blacker
Than the color of my sorrows.