Here is the attention that Apple pays to test the recording video on the iPhone.

CNET's reference to "a rare peek inside the secret labs of Apple for the camera in the iPhone 16" is a bit exaggerated, as nothing is secret: we've already had access twice or three times.

But the article does provide an interesting look at some of the testing processes used during the development of a new iPhone...

Our first looks at Apple's echo remnant back to 2018, when the company demonstrated it to The Loop. A second was presented shortly after, when Apple shared photos in a press note on the AirPods.

CNET showed some of the methods Apple uses to test microphones used for recording video sound on iPhones, demonstrated with the iPhone 16.

There is a row of speakers (about two dozen) suspended from an arched pipe that goes under the floor grid and up to the ceiling of the room. The speakers play a series of bells, while engineers measure what the microphones in the iPhone 16 Pro record. The phone, fixed on a stand mounted on a rotating base, turns a little bit to the right and the bells play again. This continues until the iPhone has turned a full circle.

The result is a spherical sound profile for each microphone, created from the recorded data in this anechoic room. Apple uses these profiles as a basis for spatial audio and other software that can reduce wind noise or make the recorded audio on the iPhone sound like different types of microphones - think of a telephone microphone or a studio microphone for voice narration.

We want to activate this [Audio Mixing] feature as if you were using a button microphone," explained Dave. "We use machine learning algorithms and our calibration chains to get this characteristic sound that you can even get with button microphones.

It's interesting to note that the main appreciation of the results is made by 'the golden ear' of Apple's acoustics lab, Ruchir Dave, but they also test different melodies with ordinary iPhone users.

In contrast to simply having someone with a good ear adjust the audio on an iPhone, Apple has a number of auditors who pass an audible perception test and then use these results to calibrate what you hear when reading on your iPhone. I even had the opportunity to be one of these testers during my stay and part of this experience [...]

Apple uses many types of comparative tests like an ophthalmologist might ask you to choose between two pairs of glasses during an eye exam. Without something to compare to, it's harder to evaluate a recording. The results of perceptual tests help influence how different aspects of the iPhone 16 Pro's sound work, including Audio Mixing.

To test videos, Apple has a video verification lab - essentially, a method for ensuring that the final result remains beautiful when viewed under many different real-world conditions.

We use this theater to calibrate reading experiences so that when you watch these videos in a dark room, in an office environment, or even under the sun, you get the same perceived experience as if you were watching a movie," said Sean Yang, director of video engineering at Apple.

Overall, it reveals no second thought, but it remains an interesting perspective on how meticulously Apple deals with small details.

Image: Apple