Netflix just upgraded the audio in its Android app to “studio-quality,” with tweaks to the audio codec that make it easier to hear in noisy environments and stop things going bad when your cellular connection falters. With this in mind, what kind of audio experience do we get from other streaming services?
Letter Soup
The Netflix Android update adds “Extended HE-AAC with MPEG-D DRC (xHE-AAC).” This seems aimed entirely at improving the mobile audio experience, by “improving intelligibility in noisy environments,” and adapting to variable cellular connections. This will, says Netflix, be a “sonic delight to members who stream on these devices.” One notable part of this new codec is loudness management, which evens things out for easier listening. For instance, action movie dialog will be made louder, so you don’t have to crank the volume to hear it. The volume level of the explosions will then be closer to the dialog. It’s a form of audio compression, only (hopefully) done in a way that doesn’t sound artificial or allow quiet background sounds to gradually creep up to a roar, as you may experience in badly ripped movies. In an excellent technical blog post, Netflix audio engineers Phill Williams and Vijay Gondi say that this even can make dialog audible over smartphone speakers in noisy environments. So, those kids watching movies on the morning metro commute are about to get even more annoying.
Other
Music streaming services often tout their audio quality, and Tidal even bases its entire reason for being on high-fidelity streaming. TV- and movie-streaming services might make a fuss whenever they upgrade to something like 4K video, but on audio, they remain quiet. Last year, Yamaha’s Ted Goslin investigated the audio and video quality of various streaming services, and if nothing else, found how fast this segment is moving. It gets even more confusing. Dolby Atmos is a surround-sound technology that can place sound in 3D space by adding height to the directional channels in regular surround sound. You find it in cinemas and in home theater devices, but the home version is not the same. It’s stripped down, despite sharing the same name. Thankfully, companies like Netflix and Apple are making things easier to understand.
Special Audio
Netflix just announced that it now has more than 200 million subscribers. 2020 was a great year for video streaming, thanks to the stay-at-home pandemic. But it is still pushing hard into mobile. This new audio format is one mobile-focused move. Another is the addition of cheaper, mobile-only plans in Africa. Meanwhile, Apple is all about mobile. Its audio tech applies almost entirely to its mobile devices, and because it makes the hardware and software for all of them, they can be integrated to a sometimes startling degree. Spatial audio is one such trick, and one that will be hard for anyone else to follow. Spatial audio doesn’t improve the audio quality of movies and TV shows. What it does is make it sound like the audio is coming from your iPhone or iPad, even as you move around. Imagine watching a movie on a TV. When you turn your head to the left, the audio from the TV speaker now hits your right ear, because the TV is now to the right of your head. Do the same thing with headphones, and the audio moves with the headphones. But not with spatial audio. No matter where you move in the room, the sound will seem to be coming from the iPhone or iPad. This trickery extends to some pretty immersive surround-sound, too. So, rather than try to battle on the quality of their sound, Apple and Netflix are tailoring it to better fit with mobile. As befits the characters of these companies, Netflix’s offer is practical and pragmatic, while Apple’s is dazzling, and pretty cool. Plus, it already solved the problem of noisy background audio with its $250 noise-canceling AirPods Pro. Either way, though, mobile streaming is getting pretty great.
