Tech Topic: Wireless | March 2014 Hearing Review

By Ross E. Dueber, PhD, and Troy W. Renken, BSEE Dueber author box

Hearing aid technology is constantly improving. Each year we see advances in such features as directional technology, digital noise reduction, feedback reduction, and automatic trainability. Perhaps the area where we have witnessed the most advances in recent years, however, is wireless technology. Once considered a “special” feature, wireless applications are now available in about three-quarters (74.6% in 2013) of all US hearing aids dispensed.1

It’s important to point out that, with hearing aids, wireless is a somewhat vague descriptor; it can refer to very different signal processing used for different purposes. Some wireless systems are simply for patient convenience, some are for feature steering, others are for improving the bilateral signal-to-noise ratio (SNR), and yet other systems are designed to interact with a different device, such as a phone, television, or remote microphone.

There do not appear to be “standard categories” of wireless applications, but the following provides a brief summary of the different features. We have simply listed the general clinical applications—several articles in The Hearing Review are available that detail wireless design and function.2-4

  • Aid-to-aid: Command codes. Commands can be sent between the two hearing aids and used to control and synchronize such things as volume control adjustment, change of program, bilateral steering for omnidirectional/directional, etc.
  • Aid-to-aid: Audio signal streaming. A full audio signal can be delivered from one hearing aid to the other. This can be used to improve the signal-to-noise ratio (SNR) by using advanced directional microphone algorithms and by maximizing the signal (right or left ear) with the best SNR.
  • Remote control. Traditional near-field magnetic induction communication to remotely change volume, programs, or other hearing aid settings.
  • Streaming. Using Bluetooth technology (usually with a relay device) for connectivity to such devices as cell phones, televisions, MP3 players, etc.
  • Companion microphones. Can transmit sounds via the hearing aid’s telecoil, or can be used through streaming devices; with appropriate positioning of the microphone, this feature can significantly improve the SNR.

There appear to be numerous advantages of wireless technology, and considerable supporting research for these advantages exist. We questioned, however, if these technologies are being routinely implemented by audiologists and hearing instrument specialists (HIS). To determine the popularity of today’s wireless products, and to assess what factors are impacting fitting decisions for this technology, we conducted a survey assessing the use of wireless features.

Dueber Table 1Survey Methods

The survey was administered to audiologists and HISs who were in attendance at three different professional meetings in the fall of 2013: California Academy of Audiology (CAA), International Hearing Society (IHS), and the Academy of Doctors of Audiology (ADA). Attendees were randomly selected from the exhibit floor at these meetings, and were given the opportunity to complete the survey (via SurveyMonkey on a laptop) if they were actively engaged in dispensing hearing aids and were familiar with all the wireless features currently available. A $10 gift card was offered as remuneration.

The survey consisted of 17 questions including basic demographic information (professional training, size of practice, years of experience, etc), dispensing patterns of wireless technology, and views regarding the pros and cons of different wireless features. A total of 101 people completed the survey, the majority of whom were audiologists (75%). There was a wide range of experience among the respondents: 28% had 10 or less years of experience, 31% 11-20 years, 26% 21-30 years, and 15% had over 30 years’ experience. Most respondents had larger practices, with 46% reporting dispensing 30 or more hearing aids/month, 44% 15-30/month, and only 10% reporting less than 15/month.

The respondents were asked to report what percent of hearing aids they purchased from specific manufacturers. As expected from the research of Johnson et al,5 the majority of respondents (66%) had a “favorite” manufacturer. The popularity of different brands was ranked similarly among the “Big Six” as has been recently reported in market share data.6

The rankings did not change significantly when the respondents were specifically asked about brands they would select when using wireless features. This suggests either that the majority were satisfied with the wireless features of their favorite company, or that they wouldn’t switch companies simply because of the wireless features of another brand.

Use of Wireless Features

We examined the general use of wireless features, and categorized them into six different functions, similar to what was mentioned earlier: bilateral control commands, audio signal streaming, streaming for external devices, streaming for mobile phone, remote microphone, and remote control (Figure 1). As might be expected, as it is the feature most readily available and easiest to implement, the most commonly used wireless feature was bilateral control commands (eg, volume, program setting, etc); three-quarters (78%) of the respondents use this feature at least 60% of the time. On the other hand, the least commonly used wireless feature was the remote microphone, with only 19% of the respondents reporting that they use this feature 60% of the time—not surprising as this feature commonly is reserved for individuals with more severe hearing loss.

Figure 1. Hearing care professionals’ preference for use of six wireless features available on hearing aids.  The percent of respondents indicates the percentage of hearing care professionals surveyed that use this feature with at least 60% of their patients.

Figure 1. Hearing care professionals’ preference for use of six wireless features available on hearing aids. The percent of respondents indicates the percentage of hearing care professionals surveyed that use this feature with at least 60% of their patients.

Note from Figure 1 that streaming for music, television, cell phones, etc, is not routinely applied. We need to point out, however, that the majority of respondents did report using these features for 40-60% of their patients, and that few stated that they seldom used these wireless features.

The responses regarding the wireless bilateral transfer of audio signals for advanced directional technology applications had a higher use rate than we expected, given that this type of processing is only available in some models from a few manufacturers. It’s possible that some respondents didn’t differentiate this feature from the more common wireless bilateral directional synchronization. In fact, when we examined the responses as a function of “favorite manufacturer,” we found this to be true—that is, some respondents who said they implemented this feature over 60% of the time also reported fitting 90-100% of products from a manufacturer that doesn’t have this type of aid-to-aid processing.

We questioned if experience level had an impact on the use of wireless features; perhaps younger dispensers are more tech-savvy and therefore are more apt to recommend these wireless technical advances for their patients? For our group data, there was not a significant effect for level of experience. Interestingly, however, when we broke out the data as a function of preferred manufacturer, there was a significant effect for one of the two manufacturers that was preferred by the most dispensers. For this manufacturer, the least-experienced audiologists and HISs were more apt to implement the following features: bilateral volume control/program control and remote microphone. A similar trend, although it did not reach statistical significance, was noted for the other leading preferred manufacturer.

Barriers to Wireless Use?

A common perception among many in the hearing industry is that wireless features are not utilized to their full potential. Is this because of rejection or indifference from the patient, or because this technology is not promoted by audiologists and HISs? Or perhaps dispensers have tried the various wireless features and found that their patients didn’t benefit?

To address this latter issue, we asked our respondents to rate the benefit they believed their patients obtained from the various features on a 4-point scale: Very Beneficial, Beneficial, Neutral, or Negative. These findings are displayed in Table 1. The features receiving the most ratings of “Very Beneficial” were synchronized volume/program control (68%), and Bluetooth mobile phone connectivity (65%). The feature given the lowest benefit rating was bilateral audio data sharing (although, for this latter technology, if we combine Very Beneficial and Beneficial, we still have a very respectable benefit rating of 73%). Consider, of course, that this is the dispenser’s projected benefit, not ratings from the patients themselves.

Certainly one factor that affects overall use of wireless technology is the “ease of use.” This issue is twofold: the ease of setup and patient orientation for the provider, and the ease of use for the patient. To address this issue, we asked our respondents to rate the difficulty level for setting up and implementing the various wireless features. We then also asked them to rate, based on patient comments or their observations, how difficult it was for the patient to effectively use the wireless feature.

Both questions were answered on a 5-point scale ranging from Very Easy to Very Difficult, and Figure 2 is a summary of both questions with the Very Easy and Easy responses combined.

Figure 2. Ease of setup by providers (green bars) and ease of use by patients (blue bars, as estimated by providers) for each of the six wireless features. The percent of respondents is the combined total of those that selected either Very Easy or Easy.

Figure 2. Ease of setup by providers (green bars) and ease of use by patients (blue bars, as estimated by providers) for each of the six wireless features. The percent of respondents is the combined total of those that selected either Very Easy or Easy.

Note that all of these features were rated “easy” to set up and program by at least 80% of all respondents. As we would expect, the highest rating for “easy” was the bilateral wireless synchronization, as for many instruments this requires no more than a single mouse click. As shown in Figure 2, the respondents believed that streaming for TV, music, and mobile phone would be the most difficult for their patients.

The data in Figure 2 is for all respondents. We should note, however, that for some wireless features, these ratings were significantly different depending on the preferred manufacturer. Most notably was the ease of programming for streaming external devices such as TV, music, and mobile phone. For example, 92% of the respondents who stated their preferred manufacturer for wireless was “Manufacturer A” rated this programming and setup as “easy,” whereas only 74% of the respondents who selected “Manufacturer B” as their preferred provider rated these wireless features easy to program and set up.

DueberFig3FPO

Figure 3. Respondents’ rating of five different factors that may limit the use of wireless features. These factors were rated on a four-point scale ranging from “Strong Factor” to “Not a Factor,” and shown here are the combined totals of the “Strong Factor” and “Moderate Factor” categories.

We also asked the respondents to rate five different factors that possibly could be preventing them from a greater utilization of wireless features for their patients. These factors were derived from an open-ended question from an earlier pilot study, and were rated on a four-point scale ranging from “Strong Factor” to “Not a Factor.” The results for this question are displayed in Figure 3, which represents the combined totals of the “Strong Factor” and “Moderate Factor” categories. As shown, the leading factor was “too complicated for patient,” followed by “increased battery drain.” While the clinical efforts for programming these features and explaining the function and operation to the patient are often quite extensive and time-consuming, this did not appear to be a major obstacle for our respondents. This was only rated as a “Strong Factor” by 7%.

Managing Excessive Battery Drain

In anticipation that excessive battery drain might be a significant factor limiting the use of wireless features,7 the final two questions on the survey dealt with this issue. The two questions were similar. We first asked what the dispenser would recommend to the patient for dealing with excessive battery drain, and then asked what the dispenser believed the patients did to manage excessive battery drain. There were seven different possible solutions, and three categories served as answers: Common, Sometimes, and Not Common. Based on an open-ended question on an earlier pilot study, seven possible recommendations/solutions for battery drain issues were obtained: A: Simply use more batteries; B: Change brand of batteries; C: Buy bulk batteries; D: Use rechargeable batteries; E: Carry extra batteries; F: Reduce use of wireless feature; G: Return to office if problem continues.

The results for these two questions are shown in Figure 4, with the likely dispenser recommendation and the predicted patient action side-by-side. Observe that what the dispenser commonly recommends is pretty much the same as what they believe is the common patient action: Carry spare batteries and simply accept the fact that this technology will use more batteries.

The Rechargeable Solution

DueberFig4FPO

Figure 4. What providers recommend and what the providers believe that the patients commonly do when dealing with excessive battery drain from use of wireless features. The seven categories listed above are as follows: A: Simply use more batteries; B: Change brand of batteries; C: Buy bulk batteries; D: Use rechargeable batteries; E: Carry extra batteries; F: Reduce use of wireless feature; G: Return to office if problem continues.

As shown in Figure 4, the use of rechargeable batteries/hearings aids is not a common recommendation from dispensing professionals. This is not surprising, since few manufacturers offer rechargeable hearing aids. But even when we examine our respondents whose preferred manufacturers do have this option, only 21% stated that this would be one of their recommendations.

Hearing aids with rechargeable batteries are not new, and have been available for nearly a decade. The advantages of hearing aids with rechargeable batteries are numerous, and have been reviewed elsewhere.8-10 To briefly review

  • Convenience. No frequent purchasing and changing of batteries.
  • Peace of mind. Assurance your battery will last all day.
  • Environmentally friendly. Fewer batteries and they are recyclable.
  • Flexibility of still using disposable batteries if a user forgets to charge the aid at night.

While all these advantages are important, the one that applies directly to the use of wireless devices is the constant knowledge that, when the patient puts on the hearing aids in the morning, the battery will last the entire day—regardless of the degree that the wireless features are utilized. This expectation is the same for leaving home with a charged cell phone. This objective also eliminates the unfortunate patient strategy of “rationing” the wireless application just to save the battery.

Improvements in rechargeable battery technology will allow this objective to be achieved. The areas of wireless technology that we expect to grow most rapidly in the next few years are:

1) Bilateral aid-to-aid real-time streaming of audio signals for special directional and noise reduction applications, and

2) Bluetooth wireless streaming to third-party devices.

These features will no doubt be available from more manufacturers, and will be added to the mid-level products, rather than just exist in premier instruments. These wireless features certainly will be the prime culprits of battery drain issues. Rechargeable batteries are a simple and effective solution with the right battery technology.

References

1. Strom K. Hearing aid sales rise 5% in 2013; industry closes in on 3M unit mark. Hearing Review.  2014;20(2):6.

2. Kossek P, Jespersen CT. How to verify wireless technology. Hearing Review. 2013;20(11):16-20.

3. Groth J, Groth T. Consumer and dispenser feedback leads to substantial improvements in 2G wireless accessories. Hearing Review. 2013;20(10):24-32.

4. Timmer B. It’s sync or stream! The differences between wireless hearing aid features. Hearing Review. 2013;20(6):20-22.

5. Johnson EE, Mueller HG, Ricketts TA. Statistically-derived factors of varied importance to audiologists when making a hearing aid brand preference decision. J Acad Audiol. 2009;20(1):40-48.

6. Kirkwood DH. Research firm analyzes market share, retail activity, and prospects of major hearing aid manufacturers. July 3, 2013. Available at: http://hearinghealthmatters.org/hearingnewswatch/2013/research-firm-analyzes-market-share-retail-stores-prospects-of-major-hearing-aid-makers

7. Joergensen HS, Baekgaard L, Bendtsen B. Battery consumption in wireless hearing aid products—Datasheet vs real-world performance. June 2013. AudiologyOnline, Article #11899. Available at: http://www.audiologyonline.com/articles/battery-consumption-in-wireless-hearing-11899

8. Yanz JL, Ellesser J, Kaempf H. Bringing rechargeable hearing aids into the mainstream market. Hearing Review. 2012;19(1):28-31.

9. Filips G. Rechargeable hearing aids: The next generation. Hearing Review Products. March 2012:8-10. Available at: http://www.hearingreview.com/all-news/17811-rechargeable-hearing-aids-the-next-generation

10. Hearing Review online. Starkey partners with ZPower to develop new rechargeable battery system for its hearing aids. Available at: http://www.hearingreview.com/products/21909-starkey-partners-with-zpower-for-to-develop-new-rechargeable-battery-system-for-its-hearing-aids.

Original citation for this article: Dueber, R., Renken, T. Survey on wireless technology features and impact on battery use. Hearing Review. 2014;21(3):42-48.