Replace the battery in your smoke detector by twisting the cover off or pulling the case off, depending on the model of your smoke detector. You may need to use a screwdriver to remove the sensor to access the battery.
Clean the smoke detector by sucking the dust out of it with a vacuum cleaner hose or a can of compressed air. This can clean out the detector and stop the beeping or buzzing noise.
Test your smoke detector by referring to the instruction manual. Every smoke detector operates differently, so do not make assumptions about what the lights or sounds mean.
Replace your smoke detector if the alarm fails to go off while testing the unit or if it won't stop beeping. Test the smoke detector several times, and if it still doesn't work properly, purchase a new one.