Unexceptional words are the best specimens for observation. They go unnoticed until you stare at them long enough to realize their endless ramifications. The word feedback is a case in point.

Being the product of a laid-back environment created by musicians and sound engineers, feedback has never had the smug undertones of other imported words that crumple the fabric of the Portuguese language. Lacking a quality that would secure it a place in the circles of cosmopolitan jargon, feedback originally became a commonplace word conveying a specific, unpleasant noise.