The IP.com Journal (v9n4A)
Juergen Carstens - Contact
email@example.com; phone +49-89-636-82995
SIEMENS AG 2009
English (United States)
2 pages / 25.9 KB
EMI shielded Telecoil Tube
Idea: Meng Kiang Lim, SG-Singapore; Wee Haw Koo, SG-Singapore; Leep Foong Chew, SG-
Telecoils are a frequently available mechanism inside a hearing aid which enables the hearing aid to be used directly with hearing-aid compatible telephones and most assistive listening devices. Telecoils pick up the electromagnetic field generated by hearing-aid compatible telephones, audio loop systems, and powered neck loops or silhouettes. The signal is then converted to sound by the hearing aid. But the telecoils are also susceptible to EMI (Electro-Magnetic Interferences) which worsens the sound quality. Thus, the improvement of the EMC (Electromagnetic Compatibility) performance and a better EMC rating of such telecoils is a mainly followed goal.
Currently, measures which are adopted to resolve the problems mentioned above are the adding of ferrite beads onto the circuitry or the plating of gold among the whole BTE (Behind The Ear) housing. These methods might not always work, the needed materials or the realization is to expensive.
It is proposed to provide the telecoil with an EMI protection by placing it in a blinded non-metallic tube which is wrapped by an EMI shielding foil. The EMI shielding foil can, if necessary, also be replaced by gold plating of the external surface of the blinded tube (Figure 1). The telecoi...