VoiceOver accessibility in a virtual musical instrument iPhone app?

I have received comments from blind users that some of my sound and music related apps only work with VoiceOver off.

With VoiceOver Accessibility enabled on an iOS device, is it possible to enable a music keyboard or drum pad touch area so that music sounds can be played immediately, instead of VoiceOver prompts, when a keyboard key or virtual drum set (etc.) is tapped?

Just setting the UIAccessibilityTraitPlaysSound AccessibilityTrait on a UIView subview doesn't seem to do it. I get VoiceOver clicking instead of piano or drum sounds with VoiceOver enabled.

A blind user can turn VoiceOver completely off, but then all the other buttons (Instrument selection, Configuration, Help, etc.) and/or controls will no longer will have VoiceOver assistance.