I recorded some fan noise using my record app. My audio recording app uses "AVAudioRecorder". Recently, I found that audio level is fade in for the first few seconds especially in iPhone 12 series.
I tested it using "voice memos" app too. I checked the same issue. I'm attaching 2 screen shots. One is from iPhone12 and the other is from iPhone11 pro max.
Could you explain why this happen? And is there any solution to prevent this?