Loudspeaker sound distributor with acoustic earphones - suitable for primary school children and amplifies sound which is otherwise inaudible

摘要

The distributor allows several people to listen to a tape recording without disturbing others. It is robust enough to be used by primary school children in their classrooms. Its two-part base consists of an outer cylinder (29) and an inner core (32), the latter containing an annular sound-chamber (41) into which reach the pick-up probes (26) of several pairs of acoustic earphones (24). The openings in the sound-chamber wall are automatically closed by sound-absorbing material (71) when the earphone probes are withdrawn. The (tape-recording-reproducing) loudspeaker is placed horizontally immediately above the annular sound-chamber, (41). It is enclosed beneath the distributor's deep, thick-walled lid and is mounted on a circumferential elastic, sound-absorbing ring.