Beard Brian B, Julstrom Stephen D
U. S. Food and Drug Administration Center for Devices and Radiological Health.
Julstrom Consulting and Development Linda K. Kozma-Spytek, Gallaudet University.
IEEE Electromagn Compat Mag. 2015 Nov 25;4(3):59-66. doi: 10.1109/MEMC.2015.7336757.
Cellular telephones (cellphones) are currently categorized for hearing aid compatibility based on a calculated value (metric) obtained from the measurement of near-field, radio-frequency emissions according to a procedure described in ANSI Standard C63.19 "Measurement of Compatibility between Wireless Communications Devices and Hearing Aids". There has been a lack of documentation, however, that relates this metric to a cellphone's potential for interference in actual use, that is, when it is held at the ear in a normal-use position by a hearing aid wearer. In Part 1 of this two-part series, we compare the ANSI C63.19 metric to simpler metrics, still based on the near-field test procedure of the standard, and to near-field measurements made when the cellphones are hand-held. The results justify employing a simpler no-hand metric than the exclusion area procedure presently specified by the standard, but not the addition of a test hand to the procedure. The further effect of the head and interaction with the hearing aid is examined in Part 2 of the series.
目前，移动电话（手机）是根据按照美国国家标准学会（ANSI）标准C63.19《无线通信设备与助听器兼容性的测量》中所述程序，对近场射频发射进行测量所获得的计算值（指标）来划分助听器兼容性等级的。然而，一直缺乏将该指标与手机在实际使用中的潜在干扰相关联的文档，也就是说，缺乏当助听器佩戴者将手机置于正常使用位置贴近耳朵时的干扰情况的相关文档。在这个两部分系列文章的第1部分中，我们将ANSI C63.19指标与更简单的指标进行比较，这些更简单的指标仍然基于该标准的近场测试程序，并且还与手持手机时的近场测量结果进行比较。结果表明，采用比该标准目前规定的排除区域程序更简单的无手持指标是合理的，但在该程序中增加测试手持情况则不合理。该系列文章的第2部分将研究头部的进一步影响以及与助听器的相互作用。
