Microphone behavior (phone, PC)

Question/Issue: Hello, I am testing audio classification and I observe quite a strange signal behavior. On both a sensor hooked up via Scarlett and a phone mic the signal was distorted. In the both cases the data acquisition was done with a phone. On Scarlett it looked like some kind of normalization. Should any signal processing happen in data acquisition with a mobile phone (or any recorder settings control)?

Project ID: 145184 (Scarlett), 145855 (mic)

Context/Use case: time series classification

Update: on PC it was possible to set up a signal flow in which the gain was stable. On the Mobile phone the gain changes with time. Is it an expected behavior or some device specific side effect?

Hi @vesperugo,

This sounds like your phone has some automatic gain control enabled. I’m not sure how to control that from the phone side. My phone (iPhone 12) worked well for recording samples for simple keyword spotting.

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