It was quite a shock, therefore, when this new metric of noisiness or annoyance seemed only to predict the annoyance of jet aircraft and not, for example, roadside traffic noise (Sounds F,G).1 It also failed to predict public acceptance of the sonic boom from supersonic aircraft, a sound that seemed to be un- acceptable (like the rattling motor) if it was heard at all. A se- nior administration official opined that supersonic flight over voting populations would never be allowed.