Soundproof Chambers and Spatial Audio Spheres: Inside Qualcomm's Audio Lab

pcmag.com:

Listening to music on your phone is more than a matter of streaming something from Spotify and putting on headphones—a lot of processing steps take place between your favorite media service, your device, and your ears. Qualcomm is one of the many companies that manage those steps, particularly when it comes to Android phones that use its Snapdragon processors.

I recently visited Qualcomm's headquarters in San Diego and toured its audio lab, where it develops and refines how Snapdragon-powered devices handle music and other audio content. While there, I also tried some of the newest features that Qualcomm's audio platform, Snapdragon Sound, will support on future phones.

Qualcomm’s audio testing lab consists of several sections across multiple floors, all with different purposes. The purest, most precise sound measurements take place in three acoustic anechoic chambers built in the lab.

Acoustic anechoic chambers are more than soundproof rooms; they’re effectively anti-sound rooms. They’re designed to enable complete silence by not only blocking all outside noise entirely but also by preventing any sort of sound reflection within the space itself. The largest of the lab’s chambers, a nine-ton box that multiple people can stand in, is mounted on vibration-dampening isolators and uses huge wedge-shaped foam sections installed on most surfaces to absorb most sound frequencies down to about 160Hz.

The lab employs two additional, smaller chambers of similar design, each just big enough to accommodate a Head and Torso Simulator (HATS), or a testing dummy about the size of a human upper body with microphones designed to precisely simulate human hearing. Testing is performed in all three chambers using a HATS, reference