1) Voice Assistant is not set on any gesture by default. Assign it to Double, Triple or Four Tap from Touch Gestures in the Noise Audio App.

2) It opens the phone’s default assistant (Google Assistant / Siri), so the assistant must be enabled on the mobile.

3) A voice prompt plays when the Voice Assistant is activated.

Note: Voice Assistant (phone assistant) and Noise AI (Tap & Hold) are two different features.