HEARING AID

According to a hearing aid comprising a voiceless period information detecting means for detecting information about a voiceless period based on sound received by a sound input means, and a control means for changing an amplification factor of an amplifying means or switching on/off output of sound emitted by a sound output means based on the sound received by the sound input means and the information about the voiceless period, output of the hearing aid can be controlled depending on noise included in the sound. Moreover, according to a hearing aid comprising a specific sound detecting means for detecting sound having specific frequency from sound received by a sound input means, and control means for changing an amplification factor of an amplifying means or switching on/off output of sound emitted by a sound output means, or making the sound output means receive either a signal passing through a filter for the specific frequency or a signal bypassing the filter, based on the sound having the specific frequency, warning sound having the specific frequency or the like appearing suddenly in ambient sound can be attenuated.