According to the World Health Organization (WHO), around 466 million people worldwide have disabling hearing loss. It may result from genetic causes, complications at birth, certain infectious diseases, chronic ear infections, the use of particular drugs, exposure to excessive noise and ageing. The organization estimates that by 2050 over 900 million people – or one in every ten people – will have disabling hearing loss.
Hearing loss may be mild, moderate, severe or profound. It can affect one or both ears and leads to difficulty in hearing conversational speech or loud sounds. “Hard of hearing” refers to people with hearing loss ranging from mild to severe. People who are hard of hearing usually communicate through spoken language and can benefit from hearing aids, cochlear implants, and other assistive devices.
Most modern hearing aids contain digital signal processors and wireless transceivers which can be affected by electromagnetic radio waves emitted by mobile phones. This is called electromagnetic interference (EMI) and can result in a degradation of audio quality and the addition of popping, clicking or noticeable gaps in the audio, and even a buzzing noise. This can happen either while people are using their mobiles or are in the vicinity of GSM-based devices.
IEC expertise handy for assistive listening devices
IEC produces international standards for hearing aids, which, like any other medical devices sold around the world, need to meet the strictest performance and safety requirements. IEC Technical Committee 29 has developed many key publications in this particular area. It has recently published the fifth edition of IEC 60118-13, which is a fundamental standard for manufacturers of hearing aids as it specifies the requirements and methods of measurement for electromagnetic (EM) immunity to mobile digital wireless devices.
“Working Group 13 of TC 29 has built a a strong relationship with the American National Standards Institute (ANSI) over the last ten years. This ongoing cooperation has resulted in the fifth edition of the IEC 60118-13 standard which specifies hearing aid positioning and EM field strengths consistent with those established in the ANSI publication which is also published by the Institute of Electrical and Electronics Engineers (IEEE)”, explains Gert Ravn who leads the working group.
“More than 1000 hearing aids have been measured since the first edition of IEC 60118-13 and these measurements have demonstrated that the field strength levels specified in the standard are sufficiently high to ensure that hearing aids are well functioning for every day use”, he adds.