Can it continue recording even while another app that is in the foreground is using the microphone? For example, suppose the user is on a phone call using Signal, can SoundHound which was last run a week ago and is backgrounded record the Signal phone call?

When you say generally no, are there exceptions? For instance, is there an exception for certain Apple apps? I wonder, if there’s a special exception that most programmers don’t know about but Apple’s engineers and some hackers do, and a mainstream iOS app is designed by people with malicious intentions, could there be a risk that such an exception, amounting to an audio backdoor, would be exploited by such a mainstream app in order to record phone calls?