If you plan to watch a show or film on Netflix Wednesday night, you might notice it sounds better. The streaming company has released a new feature called high-quality audio that makes sure what you hear is closer to what the artists behind your favorite show intended. Netflix's improved audio came about because of the show .
The first episode of Stranger Things season 2 starts off with a car chase. But when the Duffer brothers, the show's creators, first heard it played back in a living room, they noticed that the sound wasn't as crisp as the original master from the studio.
"It didn't sound quite as defined. A little bit mushy, you might say. Or like maybe there's a napkin over it," said Scott Kramer, manager of sound technology for Netflix. "Very subtle, but noticeable."
To address the issue, the show was streamed at a higher bit rate that sounded closer to the original studio master. This laid the groundwork for Netflix to create its new high-quality audio feature.
High-quality audio not only delivers a higher bit rate but can adapt to the speed of your internet connection by increasing or decreasing that bit rate. Netflix video already does something similar. If you've ever been on a slower connection, you have probably seen video playback at a lower quality until there's enough of a buffer for it to switch to a higher quality version. High-quality audio will do the same and move up and down in quality seamlessly as you watch a show.
Currently high-quality audio is rolling out to TVs and connected boxes with support for 5.1 or Dolby Atmos. Devices with 5.1 will receive a bit rate of 192 to 640 kilobits per second. If you're a Premium Netflix subscriber and have an Atmos device, playback will be between 448 and 768 kbps.
I had a chance to experience the new high-quality audio listening to a sequence from Stranger Things. There were three versions: the original master, a low bit rate one (192 kbps) and a higher bit rate one (640 kbps). The low bit rate version sounded fine, but when compared to the original master it lacked subtle audio details and clarity. The high bit rate version, to my ears, was identical to the original master achieving a phenomena called "perceptually transparent" -- don't worry, I didn't know what that meant at first either.
Perceptually transparent -- which, by the way, would be a great name for an improv group -- means there are no perceived differences between a studio master and audio that has been compressed. For Netflix streaming that perceptually transparent sweet spot was 640 kbps.
Netflix said that these bit rates might "evolve" over time as the company gets more efficient with its encoding.