You know that little chime on Facebook that bleats out when you're chatting with someone? Here, it sounds like this:

Well, that's not an off-the-shelf sound effect. It is the Facebook ping, and it was very well considered.

We know this because that ping has a fan, and that fan asked on Quora, "How much research has gone into developing the Facebook ping sound? The sound is so pleasant sometimes that it makes me wonder how much effort has been put into its development."

A flattered former Facebooker named Everett Katigbak, who "designed most of the audio currently in the product," chimed in with a most comprehensive answer.

Let's start with the best part. The chord is an F Major 7 (Fmaj7), which means it is composed of four notes: F, A, C, and E. That the perfect ping sound also spelled FACE was a "serendipitous discovery while playing with notes."

The chord had the additional good qualities, in Katigbak's estimation, that it's "a jazz chord... less formal, improvisational, and has a positive feel to it" and "contains a few interesting intervals within the chord that have certain connotations, and these form the modules for other notifications." It was improvisational and easily extensible, you could say.

"The [interesting] intervals are: 2 major thirds, F-A, and C-E. The major third trill is what is used on old school telephones," he explained, embedding this video of an old-school phone ringing.

Within the common Fmaj7 framework, Katigbak also could find "a minor 3rd interval, A-C. Descending, this interval is the same used in the common doorbell (ding-dong), which conceptually reminded me of when a friend would show up at your house," he wrote. "It is also the quintessential 'DIINNNNEERRR' or 'LAASSSIIIEEE' call out, which again, is a very nostalgic pattern."

"The audio suite was designed to be a modular system," he continued. So the various bits and pieces could be recombined to make new sounds within a common framework for different applications.

For example, take the inbound video calling sound. "It is the base arpeggio in two pulses: F-A-C-E, F-A-C-E," he wrote. (An arpeggio is simply when the notes of a chord are played in sequence.) "We went with the two pulses because this resembles a majority of international ring variations." Add it all up and this is what it sounds like.

The lesson for me is: Someone has to make every decision about every website that you visit, from the widths of the lines to the sizes of the photos to the notes in their notification sound.

While startups often run-and-gun, hoping what they make works, larger companies have a process for making things happen within their boundaries. What this means is that a company's culture and ideology really can push their way into each and every pore of a design, which is why it's worth considering the little things about the way Twitter and Facebook work and look. Fractally, they show us what the company wants to be.

As for Katigbak, he's moved on to Pinterest now. You can see more of his work at Typochondria.com.

Mashable composite. Image via iStockphoto, jvoisey

This article originally published at The Atlantic here