Radio Frequency Immunity Testing of Hearing Aids

For many Equipment Under Test (EUT), such as the hearing aids examined in this study, the desired RF immunity measurement result is that which would be measured in the most sensitive EUT orientation relative to an applied RF field. This is generally approximated from measurements at a number of predetermined orientations within a GTEM cell. This paper presents new 6 and 12-orientation "maximal sum" methods of small EUT immunity measurement, which may be considered extensions to present sorted three-input vector summation techniques. Experimental results for the new methods approached the established reference goal more consistently than did other approaches examined employing a comparable number of contributing measurements.