Preference for one or two hearing AIDS among adult patients

Abstract

Objectives: Most practitioners believe that use of two hearing aids is the ideal fitting for adults with bilateral symmetrical hearing loss. However, previous research has consistently shown that a substantial proportion of these patients actually prefer to use only one hearing aid. This study explored whether this pattern of preferences is seen with technologically advanced hearing aids. In addition, a selection of variables that were available prefitting were used to attempt to predict which patients will prefer one hearing aid rather than two.

Design: The study was designed as a 12-week field trial including structured and unstructured use of one and two hearing aids. Ninety-four subjects with mild to moderate bilaterally symmetrical hearing loss were bilaterally fit with 2005-2007 era hearing aids. Potential predictors included demographic, audiometric, auditory lifestyle, personality, and binaural processing variables. After the field trial, each subject stated his or her preference for one or two hearing aids and completed three self-report outcome questionnaires for their preferred fitting.

Results: Previous research was confirmed with modern technology hearing aids: after the field trial, 46% of the subjects preferred to use one hearing aid rather than two. Subjects who preferred two hearing aids tended to report better real-world outcomes than those who preferred one. Subjects who reported more hearing problems in daily life, who experienced more binaural loudness summation, and whose ears were more equivalent in dichotic listening were more likely to prefer to use two hearing aids. Contrary to conventional wisdom (ideas that are generally accepted as true), audiometric hearing loss and auditory lifestyle were not predictive of aiding preference. However, the best predictive approach from these data yielded accurate predictions for only two-thirds of the subjects.

Conclusions: Evidence-based practice calls for a conscientious melding of current evidence, clinical judgment, and patient preferences. The results of this research challenge practitioners to recognize that many patients who seem to be ideal candidates for bilateral aiding will actually prefer to wear only one hearing aid. Furthermore, at this time, there is no accurate method that will predict which patients will prefer one hearing aid rather than two. At present, the most effective approach open to practitioners would be to conduct a candid unbiased systematic field trial allowing each patient to compare unilateral and bilateral fittings in daily life. This might necessitate more fitting sessions and could perhaps add to the practitioner's burden. This downside should be weighed against the additional patient satisfaction that can be anticipated as a result of transparency in the fitting protocol, collaboration with the patient in the treatment decisions, and the knowledge of selecting the most cost-effective patient-centered solution.

Figure 1

Mean audiograms for men and women enrolled in the study. Bars show one standard deviation.

Figure 2

Mean NAL-R target for average speech compared to the mean real ear aided response (REAR) across frequencies. Bars show one standard deviation. Data are for the right ear.

Figure 3

The average OSPL90 value prescribed using the NAL procedure compared with the mean three-frequency average Real Ear Saturation Response (RESR) for each ear. Bars show one standard deviation. N= number of subjects.

Figure 4

Audibility of soft sounds assessed by computing the difference between pure tone thresholds (similar to 1/3 octave band levels) and the measured REAR for 45 dB speech (in approximate 1/3 octave band levels). Results are given in each ear for low-, mid-, and high-frequency bands. Bars show one standard deviation. N= number of subjects.

Figure 5

Subject preference for one hearing versus two and the level of certainly of that decision.

Figure 6

Mean audiogram depicting subjects who selected one hearing aid versus two. Bars show one standard deviation.

Figure 7

Mean scores for each subscale of the APHAB (Ease of Communication, Reverberation, Background Noise, and Aversiveness to Sounds) and the Global score for subjects who preferred one hearing aid and those who preferred two. Data are given for unaided listening. Bars show one standard deviation.

Figure 8

Results from the Binaural Test Battery for each preference group. Means (in dB) for Binaural Summation (SUM) and Binaural Squelch (SQLCH) are referenced to the left axis. Means (in %) for four scores from the Dichotic Digit battery are referenced to the right axis (REA-f=right ear advantage, free recall; REA-d=right ear advantage, direct recall; Cog-LE= cognitive effect, left ear; Cog-RE= cognitive effect, right ear). Bars show one standard deviation.

Figure 9

Accuracy of prediction of preference for one hearing aid versus two from the logistic regression model. Subjects who preferred one hearing aid are indicated by circles and subjects who preferred two hearing aids are indicated by squares. Correct predictions are shown with black symbols and incorrect predictions are shown with grey symbols.

Figure 10

Mean IOI-HA results for subjects who preferred one hearing aid and subjects who preferred two hearing aids. MM= Mild to Moderate, MS+= Moderately-severe to Severe, Adv=Advantages, Lim= Limitations. Bars show one standard deviation.

Figure 11

Mean scores on the DOSO for each hearing aid preference group for each subscale: Speech cues (Cues), Listening effort (Efft), Pleasantness (Pleas), Quietness (Qui), Convenience (Conv), and Use (Use). Bars show one standard deviation.

Figure 12

Mean benefit on the APHAB for each hearing aid preference group for each subscale (Ease of Communication, Reverberation, Background Noise, and Aversiveness to Sounds) and the Global score. Bars show one standard deviation.

Figure 13

Summary of unstructured reasons given for preferring one or two hearing aids.