Of Cicadas and High Frequency Sound

New Zealand Cicada from the Queen Charlotte Track, South Island.

I’ve heard cicadas on three continents, and they all sound different. I remember in Thailand they sounded like a constant-tone fire or burglar alarm, the high-pitched ones you hear in modern office buildings. In New Zealand, they have more of an overlapping start-stop pattern with more distinct “crrrkk”-ing, rather than a constant drone. they’d only seem to really get loud when in direct sunlight. It took me a day to finally be able to spot them consistently, get a photo (above), and then finally find some spots with minimal birdsong to record them (although I included one bellbird call in the sample below just for fun).

This post also should serve as an example to other field recordists around how specifications do not a microphone make. The Zoom H2, while handy and theoretically able to capture sound up to 20kHz, really muddies high-frequency audio content. In person, these cicada sounds were rhythmic, pulsing, and you could even hear each individual start and stop their rhythms. In the final rendered audio – sure to be made worse by conversion to MP3 for Internet posting – feels flat, inarticulate, and less interesting than what my ears heard. One just can’t expect excellent frequency response from a $200 device. Still, once again, it’s what you have with you that counts, so at least one comes away with something.

It’s worth noting that Samon has the H4n’s frequency response graph on their website, but not the H2’s. (If the same capsules used in each unit, it’s interesting how a peaks above 5-8 KHz still doesn’t always translate into improved fidelity.)

Respected wireless manufacturer Lectrosonics tests the frequency characteristics of their hardware with what they call “The Dreaded Key Test.” This consists simply of jingling a keyring with a lot of keys in front of a mic, specifically to test the reproduction of high-frequency transients. I’d recommend that anyone evaluating a microphone do this test. If the recorded sounds are articulate and discrete, that’s a pretty darned good sign. Otherwise, this test will result in tones that are harsh, indistinct, and more like a blast of static. As many other folks will recommend: Rent gear you’re interested in before you buy it, if possible!

New Zealand: Cicadas on the Queen Charlotte Track by noisejockey
[Zoom H2 recorder]