Starting today, Netflix is improving its audio quality. The company is introducing "high-quality audio", which means higher audio bitrate for Dolby Atmos and 5.1 surround.

Improved audio quality
Users with good speaker systems can now enjoy Netflix movies and TV shows in higher audio quality. Netflix says that it is taking "sound quality to another level".

- "Today we’re excited to announce a new feature, high-quality audio, which takes our sound quality to another level. We gave it this straightforward name because it fits: high-quality audio delivers audio that sounds closer to what creators hear in the studio, so every little detail is captured for a richer, more intense experience. Additionally, if you have bandwidth or device limitations, we’ve made the feature adaptive so that we will deliver the best possible audio to match your capabilities. This is similar to what we already do for video," said Netflix.

The bitrate on 5.1 surround will increase from 192 Kbps to 640 Kbps. The bitrate used to deliver Dolby Atmos will increase from 448 Kbps to 768 Kbps. To enjoy Dolby Atmos you must subscribe to Netflix's 'Premium' plan.

The company explains that improved audio quality has been implemented as an adaptive stream, meaning that users with compatible devices - and a fast enough internet connection - will automatically get improved quality. The company is also using adaptive video streaming.

Netflix added that 'high quality audio' is available for all movies and TV shows with 5.1 surround and Dolby Atmos. It is using the Dolby Digital Plus format.

- "Our high-quality sound feature is not lossless, but it is perceptually transparent. That means that while the audio is compressed, it is indistinguishable from the original source. Based on internal listening tests, listening test results provided by Dolby, and scientific studies, we determined that for Dolby Digital Plus at and above 640 kbps, the audio coding quality is perceptually transparent. Beyond that, we would be sending you files that have a higher bitrate (and take up more bandwidth) without bringing any additional value to the listening experience," the company argued.




Netflix said that it started to journey towards improved audio quality back in late 2017 after reviewing Stranger Things 2.

- "In late 2017, we were reviewing Stranger Things 2 with the Duffer brothers in a living room environment so they could understand how viewers would experience it. At one point in the first episode, there was a car chase scene that didn’t sound as crisp as it did on the mixing stage. We immediately got our sound expert involved, spun up the engineering teams and were determined to make it right, no matter how much effort it was going to take. Fortunately, we were able to address the problem for Stranger Things 2 by delivering a higher bitrate for the audio, and since then have been working diligently to roll out improved audio more broadly."

If you are curious to learn more Netflix has published a technical blog post about the project.