To provide a hearing aid preventing the degradation of an acoustic character istic and eliminating unpleasant feeling when a foreign matter is put in an auditory miatus by mounting a large-sized receiver on the outside of the external auditory miatus of an ear in the form of the so-called stereo headphone.

A headphone 1 is made so that receivers 3 may be simultaneously pushed on the both of ears 8. Two pairs of headphones 1 are connected by a connection tool 9, the headphones can are made to be mounted on the both of the ears 8 in an excellent state, the connection tool 9 is formed by the member having proper elasticity and the tool is made to come in contact with a head part 7. The receivers 3 are acoustically and loosely coupled with an auditory miatus so as not to completely close the auditory miatus and not to considerably change the acoustic nature of the auditory miatus. A circuit part 4 includes a howling prevention circuit, the circuit is mainly composed of a circuit amplifying the language voice collected by the microphone 1 and the circuit is operated because power is supplied by a switch 6 turning on/off the power source 5. The switch 6 is an automatic switch so as to turn on the power source at the time of mounting the headphone. Thus, an excellent S/N ratio is realized and the unpleasant feeling of the auditory miatus can be eliminated.