How the ambient sound at Walt Disney World works

Noah sez, "An interview with the man who designed the ambient sound at Disney World, ensuring a constant experience rather than one that ends with the end of the ride.
It was initially a little uneven, with sound changing volumes depending on where you stood, so they used algorithms to position 15,000 speakers around the park so that the levels would never change."

I like the way there's often running water or waterfalls between different soundscapes to act as a white-noise buffer. It's subtle but incredibly effective. You almost never hear two contrasting soundscapes at once.

In the mid 1990's, the park started researching the problem. It would eventually find no existing solution, so the engineers had to design and construct, on their own, one of the most complex and advanced audio systems ever built. The work paid off: today, as you walk through Disney World, the volume of the ambient music does not change. Ever. More than 15,000 speakers have been positioned using complex algorithms to ensure that the sound plays within a range of just a couple decibels throughout the entire park. It is quite a technical feat acoustically, electrically, and mathematically.

As we land, I ask Mr Q what he considers the highlight of his career. He describes how he wrote some software for "manufacturing emotion" with the thousands of new speakers in the park. The system he built can slowly change the style of the music across a distance without the visitor noticing. As a person walks from Tomorrowland to Fantasyland, for example, each of the hundreds of speakers slowly fades in different melodies at different frequencies so that at any point you can stop and enjoy a fully accurate piece of music, but by the time you walk 400 feet, the entire song has changed and no one has noticed.

How Mr. Q Manufactured Emotion

(Thanks, Noah!)