A Screening Procedure for Modified Simplex in Frequency-Gain Response Selection

Abstract

The preference for hearing aid frequency-gain responses selected using the modified simplex procedure over that prescribed by NAL-R is not universal.A screening protocol used before individualized fitting may help streamline its use and ensure effective use of clinical time. In this protocol, listeners compare the prescribed frequency-gain response with selected alternate frequency-gain responses. Evaluation with the modified simplex procedure is indicated only when listeners consistently prefer the alternate frequency-gain responses in the screening procedure. Ten hearing aid wearers completed the screening protocol and the full modified simplex procedure. In addition, subjects compared their satisfaction for the prescribed and individually selected frequency-gain responses. The results were examined for efficiency, reliability, sensitivity, and efficacy of the selected frequency-gain response. Findings revealed that the screening protocol allowed reliable identification of listeners who needed fine-tuning of the prescribed frequency-gain response. Furthermore, satisfaction for selected frequency-gain response over prescribed frequency-gain response increased as more differences between the two responses were noted. (Ear &Hearing 1994;15:62-70).Paired comparison has recently received renewed interest as a viable approach to selecting hearing aid frequency-gain response. Such interest is partly attributable to the realization that prescriptive formulae cannot guarantee optimal fitting for all hearing aid wearers. In addition, behavioral indices like thresholds and most comfortable listening levels that are important for prescriptive fittings are not free of measurement errors and can result in inappropriate prescriptive targets. On the other hand, the paired comparison technique has demonstrated sensitivity (to hearing aid frequency-gain response selection. The advent of programmable hearing aids, because of their ability to allow instantaneous switching of frequencygain responses during the paired comparison process, permits the clinical utility of this technique.There, have been various attempts to conduct paired comparison judgments in a reliable and efficient manner. They include the round-robin tournament (Punch et al, 19801, the single-and double-elimination tournaments (Studebaker et al., 1979), the National Acoustics Laboratories (NAL) approach (Byrne and Cotton, 1988), and the modified simplex approach (Neuman et al, 1987). These approaches differ in the required number of comparisons and the information that is available after the comparisons. Despite these differences, all approaches yield a recommendation of the optimal frequency-gain response for a listener. High agreement in the recommended frequency-gain response is reported among these procedures, at least for the round-robin, double elimination, and the modified simplex approaches (Neuman et al, 1987).Although the modified simplex procedure yields reliable frequency-gain response recommendations in a short time (typically less than 15 min for eva...

The Application of Binomial Probability Theory to Paired Comparison Judgments

“…Hearing aid frequency-gain responses that are ranked higher using paired comparison judgments of intelligibility are also ranked higher in speech recognition scores (Neuman, Levitt, Mills, & Schwander, 1987;Studebaker, Bisset, & Van Ort, 1980;Studebaker, White, & Hoffnung, 1978). Kuk & Pape (1993) and Kuk (1994a) also reported higher hearing aid satisfaction for frequency-gain responses selected using paired comparison judgment than those prescribed with the NAL-R formula. These characteristics, along with the ability to judge different attributes (e.g., hollowness) and different test conditions efficiently, argue that this technique has great clinical potential for individualized tailoring of optimal hearing aid settings.…”

A Patient-Centered, Provider-Facilitated Approach to the Refinement of Nonlinear Frequency Compression Parameters Based on Subjective Preference Ratings of Amplified Sound Quality

“…The paired comparison technique was chosen because it has been shown to be a more sensitive alternative to traditional speech recognition testing for differentiating hearing aid preferences, even when speech recognition is similar across conditions (Zerlin, 1962;Studebaker et al, 1982;Levitt et al, 1987;Eisenberg et al, 1998). Paired comparisons have often been used because of not only their usefulness in research, but also their application to clinical practice (Byrne and Cotton, 1988;Neuman et al 1987;Byrne, 1994;Kuk, 1994).…”

Application of Paired-Comparison Methods to Hearing Aids

“…This finding suggests that not all listeners prefer target settings. Kuk (1994a) created a screening procedure that compares the prescribed frequency-gain response to an alternate frequency-gain response. In cases where the listener prefers the alternate response, the modified simplex method is used to individualize fittings.…”

“…Eisenberg and Levitt (1991) suggest the need for a screening procedure for children, given the large intersubject variability in listeners younger than 6 years of age. The use of the screening procedure, perhaps Kuk's (1994a), could help determine whether a young child is capable of providing valid and reliable results. Further, we believe that the use of a screening procedure can be a valuable tool in determining whether a listener prefers the target response provided by various digital algorithms.…”