sound can also change our perception of product performance. (When consumers vacuum using a silent vacuum cleaner, most will tell you it’s not working. This same high degree of irrationality perhaps explains why when we vacuum the rug only to see a tiny thread on the floor, we pass the vacuum head over it stubbornly and repeatedly, even though it would be much easier to pick it up.) Human irrationality led me to ponder the following question: By altering, or even eradicating its sound, had iRobot damaged the very heart of its brand?
