Hard of Hearing Loop
First of all, hearing aids have the disadvantage for hearing impaired people that they pick up direct as well as indirect sound. For participants in conferences and churches, this has a negative effect on speech intelligibility.
The solution to this problem lies in inductive speech transmission through a hearing impaired loop. This involves connecting an antenna loop to the output of a 100 V amplifier, which is laid in the room in question or on the floor of the same. The loop generates an alternating electromagnetic field in the enclosed area, which is perceived by conventional hearing aids, as these are usually equipped with an induction coil.
Additional conditions are attached to the laying of the antenna loop. The smaller the distance between two loop turns, the higher the electromagnetic field that can be generated. The building construction also affects the strength of the magnetic field.
The antenna should not be laid directly under the seats, as reception directly above the antenna is relatively weak. The transmission quality, which is partly reduced by machines in the vicinity, can be influenced by the strength of the copper wire used as an antenna, the power of the amplifier and the distance between the loop sections.
