July 14, 2005 10:44 AM Subscribe
Recently I read an article about narrow-band sound and the attempt to develop it. For example, a siren from an ambulance on the street would clear the streets, but wouldn't wake people in their homes because they wouldn't hear it. I can't find the article and Google's no help. I'm tempted to say I read it on one of Marshall Brain's sites, but searching there was fruitless as well. Can someone find it?