Abstract: In a hearing aid support, an elongated adjustable headband surrounds the head from the forehead hairline in the vicinity of the ears to the nape of the neck. Strip forming slits in the headband at the predetermined position of the skull bone support a bone conduction oscillator to make contact with the mastoid bone.

Abstract: In a hearing aid of the type including a battery containing housing normally supported rearwardly of the ear auricle by an elongated hook joining one end of the housing to an ear opening contained ear molding, an elongated tube is secured, at it respective ends, with resilient bands which surround respective end portions of the hearing aid housing and in combination with the hearing aid housing, forms an endless configuration which surrounds the ear auricle at its juncture with the head and positions the hearing aid housing rearwardly of the ear auricle and maintains it in this position by the strand fitting snugly adjacent the user's head and forwardly of the tragus.

Abstract: In a hearing aid of the type, including a battery containing housing supported rearwardly of the ear auricle by an elongated tube joining one end of the housing to an ear opening contained ear molding, an endless flexible ring surrounds the ear auricle at its juncture with the head and a pair of flexible bands transversely surrounding intermediate portions of the ring also transversely surround, in supporting relation, the hearing aid housing to maintain it in a desired location.

Abstract: A low-pass filter passes a spectrum of electrical signals which are utilized to establish a threshold level with which electrical signals having frequencies in a relatively higher range are compared to determine if a warning sound is present in the sounds in the vicinity of a receiver unit for receiving the ambient sound. If the rectified magnitude of the signals having the higher frequencies exceeds the rectified and variably adjusted magnitudes of the signals having lower frequencies, a visual indication is given to communicate the existence of a warning sound in the ambient sounds.