It is not unusual for Google to restrict new features to the latest Pixel phone before making it available on older Pixels. They did the same with Google Lens and many other apps. One of the biggest highlights of the Pixel 4 was the audio recorder which not only recorded audio but also transcribed the same. Now Pixel 4’s audio recorded is available on older devices including Pixel 2 and 3.
The audio recorder on Pixel 4 automatically transcribes live audio and the best part is that it lets you copy the text or store it as a document. The app is known for recording high-quality audio and also lets you search for specific parts of the clip. In other words, you can simply punch in the words and the app will search the audio file for the same. Interestingly it is also capable of detecting sounds like applause or laughter within an audio clip.
I can already think of a bunch of use cases for the app. To begin with, students can use the audio recording app to transcribe lectures or perhaps a Journalist can use the same feature to transcribe an interview. The app can be downloaded via Play Store, needless to say, your Pixel should support the feature. However, the app is already available and can be sideloaded. Tread with caution though, it is not meant for other devices and might crash.
In case you are running a custom ROM, then things should be much easier. You should be able to download and install the Recorder app even on phones that are not supported.