Chances are, you've heard a difference between a National Public Radio (NPR) show like All Things Considered and some other radio talk show. NPR just has that certain sound.

One reason is that NPR hosts tend to have a certain cadence. But the signature sound is also technical. The public media news outlet Current describes NPR’s signature audio as “crisp and bright.” Last year, its podcast, The Pub, interviewed an audio engineer to figure out how exactly NPR creates its one-of-a-kind audio style.

Part of the effect comes from using specific microphones. NPR is a radio programming powerhouse, and it uses top-of-the-line Neumann U87 microphones. These microphones are specifically tuned to make NPR voices clearer to people listening in their cars by filtering out very low frequencies (below 250 hertz).

“The reason NPR came to this standard—and this was decades ago—was because most of our listeners are consuming in an automobile or with something else in the background,” audio engineer Shawn Fox tells Current. “Back in the day, and even to some degree now, you roll down those windows and hear those low rumbling frequencies. We wanted our voices to get above that so that they could be clear, open and understandable to improve our storytelling.”

The studios are also crafted to ensure high-quality audio. “We have a very low-reverberant studio, and we make sure that there aren’t a lot of solid walls,” Fox says. “Most of our facilities are all centrally located inside, right in the middle of our newsroom, so we make sure they’re isolated so you don’t hear anything else but the person speaking.”

For more sweet-sounding audio nerdiness, check out the full conversation.

[h/t Current]

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