Better can sound worse

Product & Experience

Whether we realize it or not, sound often plays a functional role in our product experience. When engineers or designers do sometimes manage to remove it, thus making the washing machine, blender or vacuum cleaner silent, trouble often ensues. The problem is that it often feels like it is no longer doing a good job; for example, researchers have found that it is very difficult to convince people that a silent vacuum cleaner is picking up anything like as much dirt as a noisier model.

A quieter vacuum can feel weaker even when it removes exactly the same dirt. Engineering improves the machine and accidentally removes part of the user’s evidence.

Mechanically, it was a nuisance. Perceptually, it had been evidence. The motor noise had joined suction in the learned meaning of “working”. Take it away and the new owner hears absence, not progress.

Specifications settle the physical question: decibels lower, suction equal, debris collected. They do not settle the first thirty seconds in a home. One participant presses the control twice. Another repeats a pass. A third empties the bin to see whether anything happened. Their behaviour expresses doubt before their survey answers do.

This offends a certain kind of product purity. A better machine should simply be better. Users ought to appreciate improvement once the numbers are explained. Unfortunately, nobody wants a tutorial before cleaning crumbs. Experience arrives first and the specification turns up later with a barrister’s wig.

The problem appears whenever old friction carried information. A heavy switch signals commitment. A clunk confirms closure. Engine sound indicates acceleration. Removing the nuisance can remove the confirmation bundled with it.

Trial seven ends with the participant kneeling to touch the carpet fibres. The observation sheet records three passes, one setting question and a lower power rating. The debris measurement matches the old model.