In 1968, he pursued a career as a contemporary artist by developing sound installations, using electronic or electroacoustic sounds which would emanate from a source within a particular space or location. He coined the term "sound installation" to describe his sound works which were neither music nor events. One piece called "Times Square" was built in 1977 beneath a grate on a traffic island in Manhattan where pedestrians would be "enveloped by a deeply resonant and mildly undulating drone, its tone suggestive of low-pitched chimes or church bells." Other works included penny whistles heard underwater in swimming pools, electronic sounds within an arboretum and the modified sounds of listeners whistling tunes over public radio.