Programatic Haptics

I'm developing an iPhone App that is using on-device speech recognition. I'd like to create a 'buzz' to confirm the word was recognised without having to look at the screen. I can get haptics working from a button; but when I try to attach sensoryfeedback to any view element, it does not fire despite my toggle from successful voice commands variable correctly flipping. Has anyone tried a similar thing with success, or have any ideas? Thanks very much.

Programatic Haptics
 
 
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