EARPHONE HAVING HOWLING PREVENTION STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide new earphone structure that prevents the occurence of howling in equipment, comprising an earphone and a microphone, such as a hearing aid.SOLUTION: A backside sound of an earphone diaphragm 1, which is an antiphase sound of a normal output sound, is conventionally confined not to come outward. The sound balances normal sound output by being simultaneously taken out from the backside of the diaphragm. Thus, howling is prevented.