Asking Siri fails on my iMac. The response is, "Siri was unable to hear you". I have checked Sound prefs, microphone and volume controls. Ask Siri is enabled. Any suggestions? Using OS High Sierra.
When you say you've checked the microphone, do you mean you've checked that it's on or that it works because you can see the level meter going up and down in System Prefs as you speak? If you've checked in Sys prefs and can't make the sound meter move try: