title: A theoretical approach to the loop induction system.
abstract: In a study of the properties of hearing aids with loop induction coils, it was observed that a group of high-powered aids used primarily for their extended low frequency responses had poor low frequency responses when used on loop input. The consequences of these characteristics are discussed. To asisst in the problem of loop design, equations are presented expressing the magnetic field strength at any point in terms of the electric current and loop location. These were found to predict the field strength with good accuracy, and may be used to calculate the field strength and its variation, produced by almost any loop configuration.
mesh_terms: D000162:Acoustics; D006310:Hearing Aids / Q000295:instrumentation*; D006801:Humans; D008433:Mathematics