Prevent reoccurring scans during tag handling

[philitell]

When my flutter-app is in foreground it is always possible to scan a nfc-tag. This mean the nfc-session is started when the app launches and it is always active. When a tag is scanned and it is Ndefformatable then i want do display a dialog to let the user confirm to format the tag with a new ndef-message. How can i disable the nfc-scan (the system sound and vibration) during handling a tag? I already implemented a lock (semaphore) to avoid reentering the onDiscovered-method. But how can i disable the sound and vibration? Or is there another way to deactivate nfc-scans during onDiscovered-method is executed?