marketrak vi isolating the impact of the volume control on

1 THE HEARING REVIEW JANUARY 2003

By Sergei Kochkin, PhD “need a VC” and consumers “who donot need a VC” have been documented ashigh as 40% (experienced users inMarkeTrak VI);■ Use of a VC is rated as a highly desirable

hearing instrument feature by 78% of USconsumers.

■ Hearing instruments, which are “easier toregulate (volume)” are on the wish list of72% of US consumers and 65% ofGerman consumers.

In my discussions with industry leaderson this topic, there have been four reoccur-ring, intriguing theories concerningMarkeTrak data on VCs. First, they questionwhether the differential in customer satisfac-tion ratings by those who want and those

who do not want a volume control is relatedto the experience of the users; it has beenhypothesized that experienced users will beless likely to want to give up the manual vol-ume control. Second, a number of peoplehave voiced the opinion that the large differ-entials observed may have nothing to do

with the presence or absence of thevolume control; perhaps the con-sumer simply received poor benefitfrom the hearing instrument andused the volume control as a “scape-goat” under the assumption that thepresence of a volume control wouldhave assured them a hearing instru-ment that provided them with more

Isolating the Impact of the VolumeControl on Customer SatisfactionDispensing professionals would do well to identify consumers’ control needs

Sergei Kochkin, PhD, is director of mar-ket development and market research atKnowles Electronics Inc, is a past officeron the Board of Directors of the BetterHearing Institute, and is past chairman ofthe Market Development Committee ofthe Hearing Industries Association.

I ncreased market penetration by complete-ly-in-the-canal (CIC) and all styles of dig-ital signal processing (DSP) hearing

instruments has led to a decline in the salesof hearing instruments with manual volumecontrols (VCs). Market statistics do not existwith respect to the number of hearing instru-ments sold in the US that do not offer a vol-ume control. However, a reasonable estimatecan be ascertained by querying theMarkeTrak VI panel. As shown in Figure 1,manual volume control penetration declinedfrom 98% prior to 1994 to 75% in the springof 2001 and 2000.

In four previous studies,1-4 the following

The strategic movement

toward automatic hearing

instruments is a positive

trend—one that will

ultimately make the hearing

instrument experience more

natural and pleasant for the

consumer. However,

categorical removal of

instrument controls,

particularly volume controls

(VCs), has undoubtedly led to

unnecessary frustration and

anger among some

consumer segments. Clearly

consumer feedback on this

issue is critical in developing

a more refined segmentation

and counseling strategy (eg,

in determining who gets the

controls and who does not).

M A R K E T R A K V I

FIGURE 1. Percent of in-the-ear hearing instruments (ie, ITE, ITC, and CIC styles) with volume controls by yearof purchase (MarkeTrak VI, n = 2,352).

has been demonstrated:

■ Approximately one-third of consumerswithout a VC desire one;

■ The difference in overall customer satis-faction ratings between consumers who


I solat ing the Impact of the Volume Control

benefit. Third, dispensing professionals andconsumers have reported that automatichearing aids work well but not in 100% oflistening situations, and that the presence ofa volume control acts as a manual override(eg, making soft sounds more audible,reducing the aversiveness of noise or loudsounds). Supporting this premise is the factthat only 42% of consumers are satisfiedwith loudness comfort. Fourth, there may besegments of users who psychologically mustbe in control of their hearing instrumentsand not the “prisoner of a signal processingstrategy” and its associated automatic gaincontrol.

This paper, the fifth in the MarkeTrak VIseries, will attempt to isolate the possibleimpact of removal of the manual volumecontrol on customer satisfaction and shedlight on some of the above issues.

MethodIn previous MarkeTrak publications,1 I

presented a detailed methodology, and read-ers are encouraged to review the methods inthe first article in this series (December 2001HR). Since incidence of hearing instrumentswithout manual volume controls has beenhistorically low, I have combined the surveyresponses of MarkeTrak V (1997) andMarkeTrak VI (2000-2001) hearing instru-ment owners concentrating on in-the-ear(ITE) hearing instruments, which were lessthan six years of age (the sample size for BTEswithout VCs was too small to be reliable).This resulted in sample sizes of 2,397 withvolume controls and 446 without volumecontrols.

Comparisons of customer satisfaction rat-ing profiles for consumer segments with andwithout volume controls are presented inTables 1-4. In Table 5, using analysis of co-variance (ANCOVA), I concurrently analyzethe impact of the VC, style (size of instru-ment), technology, as well as user level byVC interaction (eg, experienced users reactdifferently to the absence of a VC) while con-trolling for degree of hearing loss as a meansof isolating the possible impact that the lackof a VC might have on customer satisfactionratings.

Results & DiscussionConsumers are specifically asked, “Does

your hearing aid have a volume controlenabling you to adjust the volume on yourhearing aid?.” If the consumer indicates “No,”the questionnaire asks, “Would you prefer ifyour hearing aid had a volume control?”

The overall customer satisfaction resultsare graphed in Figure 2. Consumers with vol-ume controls, on average report lower cus-tomer satisfaction ratings than individualswithout a volume control (57% versus 63%).However, if results for the “no volume control”group are further segmented based ondesire/need (yes, no, not sure) for a VC, thereis a large differential between those who want a

FIGURE 2. Overall customer satisfaction based on the presence of a volume control and the desire for a vol-ume control when it is missing.

TABLE 1. Customer satisfaction as a function of stated need for a volume control (n = 430 ITE/ITC consumerswith no volume control from MarkeTrak V [1997] and MarkeTrak VI [2001]).



VC (48% satisfied) and those who indicatethey do not need a VC (75% satisfied). “Notsure” consumers report a 58% satisfaction.

Referring to Table 1, the completeMarkeTrak survey profile for these three seg-ments are reported, including differentialsbetween the “need a VC” and the “do notneed a VC” segments. It is evident that con-sumers who believe they need a VC are moredissatisfied with nearly every aspect of theirhearing aid—including a host of factors gen-erally not associated with volume controlfunction. In essence, the scope and magni-tude of the differentials point to a segment ofconsumers who are simply dissatisfied withthe total hearing instrument experience.When a hearing instrument does not workaccording to the consumer’s expectations (eg,they did not derive the benefit they need) and

they have no ability to control the hearinginstrument, then conceivably the consumer iseven more angry or disappointed in theirhearing instrument than if they had a volumecontrol.

In Table 2, customer satisfaction resultsare shown for all ITE instruments, ITEinstruments (full concha, half shell), and forITC/CIC hearing instruments. Because thereare a number of significant findings, it is use-ful to concentrate on those which are bothpractical with respect to fitting hearinginstruments and statistically significant—thatis factors with differentials of at least 10%points.

With respect to product features, thepresence of a VC negatively impacts ratingsof visibility if the hearing instrument is anITC device but not if it is an ITE device

(since the instrument is already quite visi-ble). Across the two hearing instrumentstyles, the presence of a VC would appear tobe associated with lower ratings on impor-tant performance factors such as comfortwith loud sounds,whistling/feedback/buzzing, and use in noisysituations. Consequently, this translates intolower satisfaction in a number of listeningsituations, especially outdoors, on the tele-phone (less so for ITE users because of aprobable telecoil switch), and with cellphones. ITC users report significantly lowerquality of life ratings if their hearing instru-ments have a VC.

In Table 3 results are presented for newand experienced users. Contrary to our earlierhypothesis, the experienced user is less likelyto rate their hearing instrument lower if it is

TABLE 2. Customer satisfaction with in-the-ear hearing instruments with and without volume controls (MarkeTrak V & VI, hearing aids less than 6 years of age).


lacking a volume control, while the new userdifferential is 12 customer satisfaction points(63% without VC versus 51% with VC). Forboth experienced and new users the VCwould appear to negatively impact comfortwith loud sounds, whistling/feedback/buzzing, use in noisy situations, and perfor-mance on the telephone or cell phone. Thenew user is more likely to react negatively tohearing instruments with VCs, probablybecause the presence of a VC is associatedwith the size of the hearing instrument; thesmaller the size the greater the new useracceptance of the hearing instrument. Thepresence or absence of the VC does notimpact ratings of visibility for experiencedusers, presumably because they have alreadycome to terms with the stigma of their ownhearing loss.

grammable hearing instruments areshown in Table 4. The same patternis present, though it is less evidentthen previous segment comparisons.Comfort with loud sounds, tele-phone/cellphone usage, and use inlarge groups are negatively impactedby volume controls (or consumeradjustments to the volume control).The programmable users improvedby approximately 10 customer satis-faction points on factors previouslyshown to be negatively related to thevolume control, the exception beingcell phone usage.

In order to isolate the possibleimpact of the presence or absence ofthe volume control, analysis of covari-ance (ANCOVA) was used. In ANCO-VA, the simultaneous impact of theVC, technology, hearing loss, hearinginstrument size, and experience canbe evaluated by determining its pro-portional worth/contribution to cus-tomer satisfaction. Table 5 presentsthe results for three hearing instru-ment features (VC, technology, size),as well as possible divergent userreactions to the VC. The blue barsrepresent positive contributions andthe red bars represent negative contri-butions to overall satisfaction. TheVC—when independent of technolo-gy, hearing aid size, hearing loss, andexperience—would appear to have anegative impact on comfort with loudsounds, use in noisy situations, andon the cell phone. There is some evi-dence that the lack of a VC positivelyimpacts battery life.

As previous MarkeTrak studieshave shown, advanced technologyand smaller (eg, CIC) hearing instru-ments have had a positive impact oncustomer satisfaction. There is strongevidence (the fourth column in Table5) that experienced users are more

likely than new users to derive a positive ben-efit (whether real or perceived) from the vol-ume control. They are more likely to weartheir hearing instrument more if it has a VC(while the opposite is true of new users), andthey are more likely to rate their overall hear-ing instrument experience more positively.Specifically they give higher ratings on benefit(“improved hearing”), reliability, sound quali-ty (clearness of tone, natural sounding, sound ofvoice), and value (performance vs price).Furthermore, they are more likely to ratesome listening situations more positively ifthey possess the “manual override” feature ofa VC: listening to music, leisure activities, rid-ing in a car, listening to a concert or movie,and in the workplace.

The latter information is likely to confirmdispensing professionals’ ideas about experi-enced users and VCs. Anecdotally, I have afamily member who has been a hearing aid

One would expect an interaction betweensignal processing technology and the volumecontrol. That is, instruments with advancedtechnology (DSP, non-linear programmable,WDRC, etc.) should perform better than low-tech instruments when the volume control istaken off, conceivably because the advancedtechnology should reduce the need for theconsumer to manually adjust their instru-ment when moving between listening envi-ronments (eg, phone, quiet, noisy restau-rant). In MarkeTrak, we ask consumers totell us if their hearing instrument is program-mable or fully digital. The sample size is toosmall to report on DSP hearing instruments;thus DSP instruments have been combinedwith “programmable” instruments.Comparisons between programmable (proxyfor advanced signal processing) and non-pro-

TABLE 3. Customer satisfaction with in-the-ear hearing instruments with and without volume controls; newversus experienced users (MarkeTrak V & VI, hearing aids less than 6 years of age).




wearer for more than 20 years, and now wearstwo programmable directional hearing instru-ments. He swears they are the best hearinginstruments he has ever had; his spouse iseven more thankful. In general, he indicatesthe default gain is perfect in most situations.Occasionally there are some situations wherethe gain is either too soft (the opera for him)or too loud and he does appreciate the abilityof adjusting the gain with either his remotecontrol (which he does not like to carry) orthe VCs on the instruments. I have heard sto-ries from professional associates who haveexperienced the wrath of consumers frustratedby their inability to adjust their hearing instru-ment; and I personally have received phonecalls from consumers indicating they would“never purchase a hearing instrument withoutcontrols.”

ConclusionsIdealistically, the goal is to provide hearing

rustling, bubbling of a fish tank, etc) whilesensing very loud sounds and making themcomfortable; loud sounds should never bepainful to a consumer’s ears.

Although the hearing industry has madecommendable progress in producing automat-ic hearing instruments, we need to ask our-selves if current automatic instruments are soperfect in comprehending a consumer’s listen-ing needs that a manual override will never beneeded. By removing the consumer’s ability tocontrol their listening experience, there is animplied assumption that the signal processingstrategies are indeed “perfect.” And, if we arewrong (ie, wrong enough times in the opinionof hearing aid users), then we invite unneces-sary consumer frustration, resulting in lowerthan expected satisfaction with hearing careproducts and services.

Some people need to control or adjusttheir hearing instruments either manually orwith a remote control. Research hasshown—especially among experienced wear-ers—that roughly a third of hearing instru-ment users still need either a volume con-trol, multiple memory switch (eg, “quiet”versus “noisy situation” switch), or a remotecontrol in order to manipulate volumeand/or to access different hearing aid strate-gies for handling different listening environ-ments. In a study of 79 experienced hearinginstrument users, Surr et al.5 found that 77%desired a VC even though the majority usedthe VC only “seldom” or “occasionally.”

In general, people need control of theirhearing instrument for the following reasons:

■ The automatic feature does not fully meet

instruments (or personal communication sys-tems) that are so smart that they never needadjustment. This personal communication sys-tem should efficiently determine the volumethe consumer needs and adjust its directionali-ty by sensing if the individual is in quiet or amyriad of noisy situations. It is true that con-sumers do not like to fiddle with their hearinginstruments in order to adjust optimally tochanging listening environments. Completelydigital hearing aids, when in the presence ofsteady state noise like in an airplane cabin oran air conditioner, should improve the con-sumer’s hearing comfort in these situations bymaking these loud and annoying sounds moretolerable. In addition, hearing instrumentsshould not provide annoying feedback(whistling, buzzing or squealing) as theyamplify sounds around the consumer. Hearinginstruments and assistive devices shouldrestore (or partially restore) the consumer’sability to enjoy some soft sounds (eg, leaves

TABLE 4. Customer satisfaction with in-the-ear hearing instruments with and without volume controls bytechnology (MarkeTrak V & VI, hearing aids less than 6 years of age).

Contrary to the previous hypoth-

esis, the experienced user is

actually less likely to rate their

hearing instrument lower if it is

lacking a volume control, while

the new user is 12% more satis-

fied with an automatic VC con-

trol (63% without VC versus 51%

with VC). However, research has

shown—especially among expe-

rienced wearers—that roughly a

third still need a volume control,

multiple memory switch (eg,

“quiet” versus “noisy situation”

switch), or a remote control in

order to manipulate volume

and/or to access different hear-

ing aid strategies.



TABLE 5. Isolating the influence of the volume control on customer satisfaction (MarkeTrak V & VI; hearing aids <6 years of age) using least-square-means. Blue barsmean the hearing instrument feature has a positive influence on customer satisfaction, while the red bars mean the factor has a negative influence. (Note: The short-est bar indicates the F value from the Analysis of Variance was significant at the p<0.05 level, while the longest bar indicates it was significant at the p<0.0001 level.Interaction of experience and VC means experienced users rated the presence of a VC more positive than when absent OR experienced users rated the VC more posi-tively than new users.)

their needs in 100% of listening situations;■ Psychologically, they simply have a

strong desire to control their hearingaids; or

■ They are long-term hearing aid wearerswho are used to a volume control and areunwilling to part with it through habit.

It is important that the dispensing profes-sional precisely determine the consumer’sneeds with respect to control of the hearingaid. It is true that consumers do not want tofiddle with their hearing aids every 10 min-utes; automatic hearing instruments hold thepromise of relieving the consumer of that bur-den. However, categorically removing usercontrols under the assumption that hearinginstruments perfectly comprehend all of theconsumer’s desires leads unquestionably toconsumer frustration and therefore lower cus-

tomer satisfaction ratings (especially for expe-rienced users).

Clearly, it is in the best interests of theindustry and hearing care professionals tounderstand more about the issue of consumerneeds as they pertain to hearing instrumentcontrols. It is my hope that manufacturers andhearing scientists will convene focus groupswith consumers who have experienced hearinginstruments with and without controls. Thismay lead to improved consumer segmentationand counseling strategies, resulting inimproved customer satisfaction with hearinginstruments. ◗

References1. Kochkin S. MarkeTrak VI: 10-year customer satis-

faction trends in the U.S. hearing instrument mar-ket, The Hearing Review. 2002; 9(10):14-25, 46.

2. Kochkin, S. MarkeTrak VI: Consumers rate

improvements sought in hearing instruments.Hearing Review. 2002; 9(11):18-22.3. Kochkin S. Customer satisfaction with single and

multiple microphone digital hearing aids. HearingReview. 2000; 7(11):24-29.

4. Kochkin S. MarkeTrak V: Customer satisfactionrevisited. Hearing Jour. 2000; 53(1): 38-55.

5. Surr RK, Cord MT, Walden BE. Response of hearingaid wearers to the absence of a user-operated vol-ume control. Hear Jour. 2001; 54(4):32-36.

Correspondence can be addressed to HR or SergeiKochkin, PhD, Knowles Electronics, 1151Maplewood Dr., Itasca, IL 60143; email:[email protected].

Reprinted with permission.Isolating the Impact of the Volume Control on

Customer Satisfaction, The Hearing Review, January 2003; Volume 10,

Number 1: Pages 26-35.

marketrak vi isolating the impact of the volume control on

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