Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Has a Whine of Its Own

I purchased this to cover the whine of a large central a/c unit outside my window in my apartment building. I have to warn anyone sensitive to noises like that - this unit has a whine of its own. Yes, you hear a soothing rush of air, but you can hear the whine of the motor of the Marpac underlying the air noise. Perhaps this particular unit was defective. I don't know. Maybe this would work for someone not as sensitive to noise, but I had to return mine.