Start with the simplest checks: suppress loud background noise, ensure the microphone isn’t muted, and verify the device isn’t showing a red mute light. If muted, press the mute button to turn sound back on. If it still won’t respond, unplug the device for a few seconds and plug it back in to reboot. A software update can also help; try, “Alexa, check for software updates.”
These fixes cover the most common hiccups. If you still have trouble, you may be dealing with a broader network or account issue that needs deeper investigation in the app or with your router.