A Caution Regarding External Audio Input on iOS 16.0


If you regularly connect external devices to your iPhone to work with SignalScope or SoundMeter, you may want to hold off on installing iOS 16. An apparent bug in iOS 16.0 always reports that the built-in microphone is the selected input route, even when external hardware is connected and selected. A bug report has been submitted to Apple with the hope that this issue will be resolved, soon.

This issue affects all Faber iPhone apps that can run on iOS 16:

  • SignalScope X
  • SoundMeter X
  • SignalScope Basic 2018, 2020
  • SignalScope Advanced 2018, 2020
  • SignalScope Pro 2018, 2020
  • SoundMeter Basic 2018
  • SoundMeter Pro 2018, 2020
  • New 2022 apps, which are coming soon

Note that this issue only affects the iPhone versions of these apps. No such issue has been found when running Faber apps on iPad or Mac.

If you have already installed iOS 16, you can still work with external devices–it may require more careful attention to get accurate measurements. Here are some notes that should be helpful in that case.

  • On iOS 16.0, the app will always indicate that the built-in microphone is the selected input device (unless you select the built-in accelerometer in SignalScope), so care must be taken to ensure that the desired external device is selected. Test measurements may be required for this. For example, if you are working with an external microphone, you can monitor its signal in the Oscope or FFT Analyzer and excite it somehow to be sure the signal is coming from that mic rather than from the built-in mic.
  • The external device can be selected by plugging it in, or by manually selecting it (if it’s already plugged in) in the Input Device selection menu in the app. This hasn’t changed, but since iOS 16 still reports the built-in mic as the current input, the app won’t recall any previously-saved or default preferences for the external device (such as device/channel units, device/channel sensitivities, gain selection, etc).
  • The correct number of input channels will be available for the external device, so input units and sensitivities can be properly set for each channel of the external device (that is, you can still work with multi-channel input hardware). Note that these settings will be saved for the built-in mic, so if/when this bug in iOS 16 gets fixed, they won’t then be recalled for the external device when it is properly recognized (whatever values were previously saved for the external device will be recalled).
  • Supported sample rates of the external device can still be used (e.g. 192 kHz for external hardware that supports it).

Update: This issue has been fixed as of iOS 16.1.