Digital hearing instruments as a percent of fittings have grown from 5% in 1998 to nearly 90% in 2005.1 In terms of active hearing instruments in consumers' ears over the last 5 years, nearly half of consumers (48%) are using hearing instruments with digital signal processing (DSP). A study of customer satisfaction with hearing instruments is especially relevant at this time when there are nearly 5 million digital hearing instrument fittings in the marketplace. With a binaural rate of 74%, this equates to 2.9 million users of DSP instruments.
It is generally agreed that digital hearing instruments offer significant advantages to the hearing-impaired that 10 years ago were not available with analog hearing instruments:2-7 These include:
v Superior signal processing (DSP) capabilities, increasing the chances that noise sources will be removed and that the instrument will capture and understand more of the speech signal, or that some sounds will be enhanced to aid speech intelligibility.
v Active noise reduction and cancellation and therefore greater user comfort in noisy situations.
v Greater flexibility in fitting the instrument to the unique hearing loss characteristics of the consumer.
v Better ability to reduce internal noise in the hearing instrument through suppression of acoustic and mechanical feedback.
v Superior optimization of microphones in directional hearing instruments.
v Better overall shaping of the frequency response.
v The ability, through datalogging, to use DSP to better monitor hearing instrument use, which will aid the fine-tuning process for some consumers.
v Overall cleaner sound delivered to the consumer's ears.
In a survey of hearing instrument specialists and audiologists, most reported greater patient satisfaction with digital hearing instruments.8 Dispensers reported that their patients were either “somewhat” or “much more satisfied” with DSP in comparison with older technology as follows: overall satisfaction (78% believe DSP is better for their patients), sound quality (89%), listening comfort (82%), understanding speech in noise (77%), understanding speech in quiet (62%), feedback suppression (70%).
In a double-blinded comparison of three levels of hearing instrument technology, 74% of consumers preferred the second-generation digital over a single-channel analog programmable and a first-generation, two-channel DSP.9 The advanced digital was rated significantly higher on word recognition, need fulfillment as measured by the Client Oriented Scale of Improvement (COSI), numerous listening situations, situational preference (i.e., speech in noise), and overall preference.
This article is the second installment of a series of publications that will cover significant issues and trends in the hearing instrument market. Its purpose is to explore in detail the customer satisfaction ratings of hearing instruments, with an emphasis on fittings over the past 5 years.
In November 2004, a short screening survey was mailed to 80,000 members of the National Family Opinion (NFO) panel. The NFO panel consists of households that are balanced to the latest U.S. census information with respect to market size, age of household, size of household, and income within each of the nine census regions, as well as by family versus non-family households, state (with the exception of Hawaii and Alaska), and the nation's 25 largest metropolitan statistical areas.
The screening survey covered only three issues: (1) physician screening for hearing loss, (2) whether the household had a person “with a hearing difficulty in one or both ears without the use of a hearing aid,” and (3) whether the household had a person who was the owner of a hearing instrument. This short survey helped identify close to 16,000 people with hearing loss and also provided detailed demographics on those individuals and their households, which was reported in the first publication in this series.10 The response rate to the screening survey was 66%.
In January 2005, an extensive survey was sent to 3000 random hearing instrument owners and 3000 random people with hearing loss who had not yet adopted hearing instruments. The response rates for the detailed surveys were 75% and 77%, respectively.
The data presented in this article refer only to households as defined by the U.S. Bureau of Census, that is, people living in a single-family home, duplex, apartment, condominium, mobile home, etc. People living in institutions have not been surveyed; these would include residents of nursing homes, retirement homes, mental hospitals, prisons, college dormitories, and the military.
Detailed demographics of the hearing instrument owner population are documented in the first publication,10 so they will not be repeated here. In evaluating customer satisfaction with hearing instruments and hearing health services, this paper will focus on hearing instruments less than 6 years of age (n=1511). The hearing instrument owners responded to a seven-page survey consisting of 188 questions or response scales in the following areas: hearing instrument owner demography, hearing loss measures, product features, customer satisfaction and usage, future behavior, factors influencing hearing instrument adoption, and perceptions of hearing health providers.
With respect to customer satisfaction measurement, consumers were asked to rate their hearing instrument experiences on 46 items, using a 7-point Likert scale: “Very dissatisfied,” “Dissatisfied,” “Somewhat dissatisfied,” “Neutral” (equally satisfied and dissatisfied), “Somewhat satisfied,” “Satisfied,” and “Very satisfied.” The attitude items covered overall satisfaction, product features, product performance, dispenser service, and satisfaction in 15 listening situations.
Table 1 documents the hearing loss characteristics of the hearing instrument owner population responding to the customer satisfaction survey as well as information concerning their hearing instruments. The average age of respondents is 71, 6 out of 10 are male, and household in-comes are slightly more than $53,000; the majority (64%) are married and retired (66%) and 62% have attained a high school degree or less.
Regarding their hearing loss, 84% report bilateral loss and (52%) subjectively evaluate their loss as “moderate”; 48% report their best level of hearing is the ability to “hear a shout across a room” (Gallaudet scale), and on average they report difficulty hearing in the presence of background noise about 60% of the time (Unaided Abbreviated Profile of Hearing Aid Ability).
With respect to product features, three-fourths indicate they wear binaural hearing instruments. The modal style is “a visible in-the-canal” instrument (41%). The reader will recall that 48% of hearing instruments fitted over the last 5 years were digital; 47% of this sample reported their instruments were digital. One in four consumers report their hearing instruments have directional and telecoil features and 7 out of 10 report they have a volume control. Only 6% have a remote control and fewer than 1% indicate they have FM on their hearing instruments.
RESULTS AND DISCUSSION
Before examining the detailed findings, it's useful to consider the top 10 factors related to overall customer satisfaction with hearing instruments in this sample. In rank order the factors that are most correlated with overall hearing instrument satisfaction (correlation in parentheses) are:
1. Overall benefit (.74)
2. Clarity of sound (.72)
3. Value (performance of the hearing instrument relative to price) (.69)
4. Reliability of the hearing instrument (.69)
5. Natural sounding (.68)
6. Ability to hear in small groups (.66)
7. Richness or fidelity of sound (.64)
8. One-on-one conversation (.63)
9. Leisure activities (.63)
10. Listening to TV (.62)
These are the factors that tend to co-vary the most with overall satisfaction. The implication is that incremental improvements in these areas will drive improvements in overall satisfaction. The factors least correlated with customer satisfaction are:
1. Visibility of hearing instrument (.34)
2. Hearing instrument usage: hours worn (.36)
3. Front office staff (.38)
4. Ease of changing battery (.41)
5. Battery life (.41)
6. Ease of adjusting volume (.44)
7. Dispenser service (.46)
8. Packaging (.48)
In Table 2, we have referenced the detailed ratings for the 46 satisfaction items, hearing usage (hours worn), and three behavioral measures. The figures to follow collapse the satisfaction into three categories: dissatisfaction (red), satisfaction (green), neutral (not shown).
Overall indices (Figure 1)
Customer satisfaction with hearing instruments less than 6 years old is currently 71%; 85% of consumers are satisfied with the benefit they get from their hearing instruments, while nearly two-thirds (64%) believe they have received good value in their purchase.
For comparison purposes, we have plotted the satisfaction ratings for these three variables in Figure 1b for the total population of hearing instrument owners based on the age of the instrument. For hearing instruments less than a year old, the ratings are stellar: 90% satisfaction with benefit, 78% overall satisfaction, and 72% with value. Although ratings drop over time, customer satisfaction with benefit is nearly 80% for products 6–9 years old, while overall satisfaction is 66%.
Another way of determining satisfaction is to measure the percentage of hearing instrument owners who actually wear their hearing instruments. Nearly 9 out of 10 currently wear their instruments; a hearing aid user is defined as someone who wears his or her hearing instrument at least once a year. However, perhaps a better behavioral measure of satisfaction can be derived from consumers who wear their instruments at least 4 hours a day. In the latter case, one could say that three out of four consumers are satisfied with their hearing instruments. It should be noted that the correlation between overall satisfaction and usage is only modest (r=.36).
Behaviorally the ratings for hearing instruments are strong. Eight out of 10 (79%) current users would recommend hearing instruments to their friends and 7 out of 10 (73%) would recommend the person who fit them with hearing instruments. However, only 44% indicate they would repurchase their current brand of hearing instrument next time around; a large percent (43%) indicated they were unsure what they would do when it came time to replace their instruments.
More than nine out of ten (93%) consumers indicate that their quality of life has been positively impacted by their hearing instrument usage at least “some of the time.” Areas most affected (“better” or “a lot better”) by hearing instrument usage are in rank order as follows (see Figure 1c):
v Seven out of 10 cite more effective communications.
v Five in 10 say their social life, ability to join in groups, relationships at home, feelings and confidence in self, sense of safety, and relationships at work have improved due to hearing instruments.
v Four in 10 report improvements in their sense of independence and emotional health.
v About a third report improved mental/cognitive ability.
v One in four report improved physical health.
Product features (Figure 2)
Except for fit and comfort (86% satisfaction) and reliability (79%), most items in this category should be considered of secondary importance in terms of their potential to impact customer satisfaction. The lowest correlate of overall satisfaction, “visibility of hearing instrument,” garners a 78% customer satisfaction rating. The item receiving the most negatives in this category is battery life; nearly one in five consumers are dissatisfied with the battery life of their hearing instruments, while seven in ten are satisfied.
Signal processing and sound quality (Figure 3)
This is clearly the most important category to the consumer, since it includes three of the top ten correlates of overall customer satisfaction: clarity of sound, richness of sound/ fidelity, and naturalness of sound. Three out of four consumers are satisfied with the clearness of the tone and the sound of their instrument; seven out of ten are satisfied with their voice and believe the instrument is natural sounding. Two out of three are satisfied with their ability to tell the direction of sounds and their ability to hear soft sounds.
Only six out of ten are comfortable with loud sounds, while one out of four is dissatisfied; slightly more than half are satisfied with the ability of their hearing instruments to control annoying feedback and the sound of chewing or swallowing. Only half are satisfied with wind noise and their instruments in noisy situations. Clearly there is a major opportunity for manufacturers and dispensers to improve the consumer's experience on these factors.
Consumer satisfaction in selected listening situations (Figure 4)
MarkeTrak measures satisfaction in 15 listening situations. Ninety percent of consumers are satisfied with the ability of their hearing instrument to improve communication in one-on-one situations, and slightly more than eight out of ten are satisfied by its performance in small groups and while watching television. About three of four consumers are satisfied with their instruments outdoors, while listening to music, while participating in leisure activities, in the car, at a house of worship, and in a restaurant. Seven out of ten are satisfied with their instruments at concerts and movies and on the telephone. Among those still in the workforce, two out of three are satisfied with their hearing instruments.
The three most difficult listening situations are in large groups (63%), school/classroom situations (59%), and while using a cell phone (59%). Three listening situations received a dissatisfaction rating from one in five consumers: using the telephone, using a cell phone, and large group situations.
Figure 4b shows the powerful impact of improving multiple environmental listening utility (MELU) for the consumer. In this chart, we are expressing MELU as the percent of environments (from our list of 15) in which consumers are either “somewhat satisfied,” “satisfied,” or “very satisfied” with their aided hearing. Consumers who are not satisfied in any listening situation (they could be dissatisfied or neutral) can be expected to be satisfied with their hearing instruments only 17% of the time. Consumers who achieve satisfaction in half of their listening situations report an overall satisfaction rating of 63%. Clearly, consumers expect their hearing instruments to perform in most of the listening situations they encounter. We are estimating that hearing instruments must provide value (i.e., listening utility) in 70% of listening situations to achieve an 80% or higher overall customer satisfaction rating.
Using the MELU yardstick measure on hearing instruments less than 6 years old, we are estimating the following (see Figure 4c):
v 7% of users are satisfied in no listening environment (not even one-on-one).
v 18% of users are satisfied in 25% or fewer listening situations.
v 61% of users are satisfied in 80% or more listening situations.
v 42% of users are satisfied in 100% of listening situations.
The dispenser experience (Figure 5)
In general, most of the ratings of dispensers (the person who fit the hearing instrument) are impressively high, exceeding 90% in consumer satisfaction. The lowest rated area is post-purchase service at 87% satisfaction.
According to consumers, dispensers spend on average three-quarters of an hour (std=.6 hours) instructing them on the use and care of their hearing instruments, explaining hearing instrument features and styles, and creating realistic expectations. The average dispenser spends half an hour (std=.5 hours) on aural rehabilitation counseling, which could include communication techniques, lip reading, exploration of feelings about hearing loss, etc.
Six out of ten consumers indicate that it took only one or two visits before their hearing instrument sounded just right to them; about one in four indicate between three and five visits, while 12% indicate their hearing instrument is still not right. Overall, consumers report that it took 2.5 visits (std=1.6 visits) before they were satisfied with the instrument's sound quality and two visits before they had gained competence in caring for their hearing instrument (i.e., cleaning, storing, operation, battery change, etc.). Thirty-six percent of consumers indicate they have never had to return their hearing instrument because it was wasn't working; the average returns for service were 1.6 (std=1.7 returns). Of those returning their instruments, 79% are satisfied with the service they received.
The impact of digital technology (Table 3)
In MarkeTrak we query the consumer on the presence or absence of certain features on their hearing instruments. One such factor is whether or not their hearing instrument is digital. Forty-seven percent of consumers indicated “yes” to our question, and 53% “no” or “not sure.” The reader will recall that 48% of hearing instruments sold over the past 5 years were digital.
In Table 3, after controlling for age of instrument, presence of multiple microphones, telecoil, and binaural usage, 27 of the 56 MarkeTrak items are shown to be significantly higher if the consumer identifies the product as digital. Focusing on factors with a “practical” significance of 10% point satisfaction, the most notable improvements associated with digital hearing instruments in rank order are:
v 20% points higher: comfort with loud sounds.
v 15%-19% points higher: richness or fidelity of sound, feedback suppression, use in noisy situations, wind noise, use in workplace.
v 10%-14% points higher: overall satisfaction, clarity of sound, sound of voice, natural sounding, localization of sound, able to hear soft sounds, sound of chewing and swallowing, use outdoors, listening to music, leisure activities, at a concert/movie, on the telephone, in school/classroom situation, on a cell phone.
Satisfaction and severity of hearing loss
Consumers were segmented into one of five groups (called quintiles) based on their responses to four measures of hearing loss:
v Number of ears impaired (1 or 2)
v Score on the Gallaudet Scale (an 8-item inventory taking the values “can hear a whisper across a room” to “cannot hear loud sounds”)
v Score on the Unaided Abbreviated Profile of Hearing Aid Benefit (APHAB), an inventory of how difficult it is to hear without hearing instruments in 18 listening situations. The APHAB consists of four scales: ease of communication (EC), reverberation (RV), background noise (BN), and aversiveness of sounds (AV). We did not administer the AV subscale and we changed the scaling to 0% to 100% of the day in 10% increments. Based on a factor analysis of BN, EC, and RV, which revealed that the APHAB was one-dimensional, the unaided APHAB score for each individual was the mean of the three subscales.
v Subjective hearing loss score: mild to profound (a score of 1–4)
A factor analysis of these subjective measures was performed revealing a single measure of hearing loss. Factor scores were computed and each consumer was placed into one of five groups in which Quintile 1=the mildest hearing loss, the lower 20% of people with hearing loss, and Quintile 5=the most serious hearing loss, the 20% of people with the greatest hearing loss. Customer satisfaction measures are documented in Table 4 for each of the five hearing loss groups, as well as difference scores between the mildest and most severe hearing loss group, and an indication as to whether there are significant differences in satisfaction based on severity of hearing loss.
There were no significant differences on overall measures of satisfaction, product features, or dispenser service. However, the majority of sound quality/signal processing variables show significant differences in satisfaction based on hearing loss severity. When comparing mild and severe hearing loss, the most notable are: comfort with loud sounds and ability to hear soft sounds (19% points), wind noise (18%), and ability to tell direction of sounds (17%). With respect to listening situations, satisfaction was related to severity of hearing loss in 13 of 15 listening situations. The most notable are: cell phone (28% points), school/classroom situations (18%), large group (17%), telephone (17%), concerts (17%), and listening to music (15%).
In a survey of more than 1500 current users of hearing instruments, half of which were digital, overall customer satisfaction was measured at 71% for hearing instruments 0–5 years old. Customer satisfaction with 1-year-old instruments was 78%, which placed hearing instruments in the top third of all products and services in the United States as measured by the University of Michigan.11
Hearing care professionals received stellar ratings approaching perfection. Overall they achieved a 92% satisfaction rating.
Eighty-five percent of consumers are satisfied with the ability of their instruments to improve their hearing, meaning they are deriving tremendous benefit. In 15 listening situations, customer satisfaction ranges from 90% (one-on-one) to 59% (cell phone). Six out of ten consumers are satisfied with their instruments in 80% of the listening situations measured in this study.
Hearing instruments are beneficial all along the hearing loss continuum. However, ratings are significantly lower for the severe-to-profound hearing loss population (i.e., the 20% of people with the most severe hearing loss). Significant opportunity remains to meet the needs of people with the greatest hearing losses. For example, fewer than 1% of consumers own an FM assistive listening system and only 25% use directional microphones or telecoils.
The use of digital hearing instruments is associated with significantly higher ratings on overall satisfaction and benefit, improved sound quality, reduction in feedback, improved performance in noisy situations, and greater utility in a number of important listening situations.
This study was made possible by a special grant from Knowles Electronics, LLC, Itasca, IL.
© 2005 Lippincott Williams & Wilkins, Inc.