Tech Topic | July 2020 Hearing Review

By David James Crowhen, MAud, and Charlotte Gordon, MAud

Remote microphone technology (RMT) continues to become more effective and smaller, as well as faster and easier to set up. This field trial demonstrates how the new RogerDirect system makes it faster and easier for hearing care professionals to employ RMT technology in hearing aids.

Hearing loss affects our ability to hear and therefore communicate, especially in background noise.1 Recognizing that people with hearing loss experience greater difficulty hearing in noise, directional microphone (DM) technology was developed in hearing aids. DMs help improve the signal-to-noise ratio (SNR) when facing the signal of interest, improving speech understanding in noise in the near-field (Figure 1). However, as the signal of interest moves farther away into the far-field, hearing aids alone are often not enough.  This is because the signal becomes substantially degraded by the time it reaches the hearing aid microphone, limiting benefit to the listener.   

Figure 1. Schematic diagram mapping noise and distance, defining the near vs. far field and outlining which technologies will deliver optimal performance across the soundscape.

Children face this scenario on a daily basis. For example Mulla and McCracken2 reported that preschool children spend around 40% of their time listening from a distance and in noise. Because they lack linguistic redundancy, the impacts of a degraded signal are even more pronounced for children than for adults. Children require higher sensation level SNRs3 and lower reverberation4 to achieve performance parity with adults. 

If children are not hearing well, it can negatively impact their school performance5 and psychosocial wellbeing.6 Inadequate amplification can also limit a child’s serve and return interactions, which are integral to normative language development and neuronal architecture.7 These challenges can be an extreme detriment to children with hearing loss, and highlight the importance of a robust and easy-to-use hearing solution to improve listening outcomes in complex listening environments. 

The benefit of Roger™ technology is not limited to children; adults with hearing loss also have complex needs where they are required to listen at a distance and in noise. These are common scenarios where Roger technology would significantly improve hearing performance. This is demonstrated by a recent survey, where 42% of HCPs said that more than half their clients had far-field hearing needs.8

Remote microphone technology (RMT) was developed to overcome the challenges associated with hearing at distance. A microphone is worn by, or placed near, the speaker of interest. This picks up the signal and wirelessly transmits it (using either FM, Bluetooth, or Roger™ technology) to a receiver either worn around the neck or attached to a hearing aid(s), or more recently installed into the hearing aid itself. 

There are fixed and dynamic systems. Dynamic systems, especially Roger, adjust their behavior in response to changing background noise levels to help keep the signal audible. This dynamic behavior has been shown to provide significantly better performance than fixed systems at higher noise levels.9-11 Unfortunately, higher noise levels are common in classroom environments. For example, Park12 measured average noise levels of 75 dBA in modern learning environments in New Zealand. Roger has the added advantage of offering MultiTalker Network (MTN) capabilities, where multiple transmitters can deliver signals from multiple sources (eg, questions from classmates, meetings around large boardroom tables, media from TV etc..), thus improving hearing performance.13,14

Despite the well-established benefits of Roger technology for optimizing hearing in complex listening situations, some barriers to uptake exist, including increased hearing aid size due to the need for an external receiver, complexity of ordering and set-up by the clinician (eg, determining receiver compatibility, physically attaching the external receivers, etc), and ease of use.15 RogerDirect™ technology was designed to overcome these barriers by streaming the signal directly from the Roger microphone(s) to the hearing aids. It removes the need for external receivers and makes set-up quick and easy, without compromising the proven performance of Roger technology. 

The goals of the following field trial were to: 

1) Determine if hearing aids with RogerDirect are faster to set up than traditional Roger systems;

2) Determine if hearing aids with RogerDirect are rated as easier to set up than traditional Roger systems, and

3) To understand the perceived benefits of RogerDirect for hearing care professionals (HCPs) and their clients.

Method

A total of 47 HCPs from across New Zealand took the opportunity during launch events to gain hands-on experience with the new hearing aids with RogerDirect. Thirty of the HCPs installed Roger receivers into a Marvel hearing aid using a Roger X and Roger installer, while the remaining 17 used the Roger Select iN transmitter. (Step-by-step instructions were provided; see Appendix 1 below.

To enable a comparison to Roger fittings without RogerDirect, participants were also asked to remove a battery door from—and attach a Roger 19 external receiver to—a Naida V-UP hearing aid. The time taken for HCPs to install the Roger receiver into Marvel hearing aids with RogerDirect and the time taken to attach a traditional Roger external receiver was recorded. Alongside these tasks, we asked HCPs to rate the ease of each technique, as well as to compare them in terms of which technique they perceived was easier. Finally, we asked the HCPs to list three perceived benefits RogerDirect may provide to themselves and three benefits they could envisage for their clients (See Appendix 2 below for the full questionnaire).  

Appendix 2:

  1. Please time how long it took you to INSTALL the Roger receiver into the Phonak Marvel hearing aid (full procedure as per the step-by-step instructions)

             Min ________________      Sec: __________________       

2. Please time how long it took you to UNINSTALL the Roger receiver into the Phonak Marvel hearing aid (full procedure as per the step-by-step instructions)

             Min ________________      Sec: __________________      

3. Please rate the effort/ease to install and uninstall the Roger receiver into the Marvel hearing aid

12345
Very easyEasyOKFiddlyVery difficult

4. Please time how long it took you to attach the Roger integrated receiver to the previous platform hearing aid? 

Min ________________      Sec: __________________       

PTO

5. Please rate the effort/ease to attach the Roger integrated receiver to the previous platform hearing aid? 

12345
Very easyEasyOKFiddlyVery difficult

6. Please rate how you found it to install the Roger receiver versus fitting an integrated Roger receiver to a hearing aid?

12345
Far easierEasierAbout the sameSlightly harderFar harder 

7. What are the top 3 advantages can you see RogerDirect providing your CLIENTS relative to the previous Roger solutions? 

  1. ____________________________________________________________________
  2. ____________________________________________________________________                                     
  3. ____________________________________________________________________

8. What are the top 3 advantages can you see RogerDirect providing YOU/YOUR CLINIC relative to the previous Roger solutions? 

  1. ____________________________________________________________________
  2. ____________________________________________________________________                                     
  3. ____________________________________________________________________

Results

Data were checked for adherence to a normal distribution, and parametric or non-parametric statistical tests applied accordingly. Because no significant difference was found in terms of the time taken to install Roger receivers using either a Roger X and Roger Installer or a Roger Select iN transmitter (Kolmogorov-Smirnov test, P= 0.1174), data were pooled for subsequent analysis. Approximately 75% of participants were faster at installing a Roger receiver into a Marvel hearing aid with RogerDirect versus attaching an external Roger 19 receiver to a Naida V-UP hearing aid. The median time taken for installing a Roger receiver into a Marvel device was 27.5 seconds, compared with 37.6 seconds for attaching a Roger 19 external receiver to a Naida V-UP hearing aid (Figure 2). A Wilcoxon matched-pairs signed rank test showed this difference was highly significant (P <0.0001). It follows that the median time for setting up a binaural Roger system using a Select iN transmitter should be less than 1 minute. 

Figure 2. Time taken for installing a Roger receiver into a Marvel hearing aid versus the time taken to attach an Roger 19 external receiver to a Naida V UP.

Subjective ratings showed that 93% of participants rated it as either “very easy” or “easy” to install the Roger receiver into a Marvel hearing aid (Figure 3A) In contrast, only 38% of the HCPs rated it as either “very easy” or “easy” to attach the Roger 19 external receiver to the Naida V-UP hearing aid (Figure 3B).  Interestingly, there was no significant relationship between the ease ratings and the time taken to install a Roger receiver (Kolmogorov-Smirnov test, P= 0.2612).  

Figure 3A-B. Left panel (A): Ease ratings for installing Roger receiver into a Marvel hearing aid. Right panel (B): Rated ease of attaching a Roger 19 external receiver to a Naida V UP. 

This may be related to the finding that 64% of participants who did not realize a time advantage with installing a Roger receiver into a hearing aid with RogerDirect still rated installing the receiver as either “far easier” or “easier” than attaching an external receiver (Figure 4A). When considering all participants, 81% rated it was either “far easier” or “easier” to install a Roger receiver into a hearing aid with RogerDirect (Figure 4B).

Figure 4A-B. Left panel (A): Ease ratings for those who had either no time difference or were quicker at attaching an external Roger 19 receiver versus Roger receiver with installer. Right panel (B): Ease rating comparison of Roger receiver installation versus attachment of external Roger 19 receiver to Naida V UP. 

In contrast to the lack of relationship between the time taken to install a Roger receiver into a Marvel hearing aid and rated ease, a significant relationship was found between the time taken to attach the external Roger receiver to the Naίda V-UP and the rated ease of the process (Spearman r=0.6057, P<0.0001), where longer times were associated with lower-rated ease. Additionally, a significant relationship was found when comparing time difference and rated ease between the two Roger receiver installation methods (Spearman r=.548, P=0.0003), where larger time differences were positively associated with larger differences in rated ease between the two. 

For the Roger iN transmitters, installing the Roger receiver automatically connects the Marvel hearing aid with RogerDirect to the transmitter. For Roger X installation, the transmitter only has to be connected to one Marvel hearing aid for the Roger signal to be received binaurally. To get an estimate of total set-up time we also recorded the time taken for a cohort of 12 participants to connect a Roger transmitter to one Marvel hearing aid. The median time was 17.8 seconds (LQ=13.74, UQ=27.98). It follows that the median time for setting up a binaural Roger system using a Roger X and Roger Installer should be less than 1 minute 20 seconds. 

Lastly, participants were asked to list the benefits they could see RogerDirect providing both themselves and their clients. Responses were categorized into themes and the results are summarized in Figure 5A and 5B, respectively. 

Fig. 5A-B. Count of reported anticipated benefits of Roger Direct for HCPs (upper panel, A) and for clients (lower panel, B). Note that participants were asked to list three benefits for each group, and some reported benefits that fall within the same theme.

Discussion

RogerDirect has been designed to overcome some of the barriers to the uptake of Roger—especially ease of set-up, ease of use, and cosmetic concerns. Results of this study show that participants found it easier to install a Roger receiver into a Marvel hearing aid with RogerDirect versus attaching an external receiver to a previous-generation hearing aid. In fact, three-quarters of participants were faster installing the receivers with RogerDirect than with the Roger 19 external receivers. No relationship was found between time taken and ease ratings for installing the receivers. On face value this may seem counterintuitive; however, it is likely related to the fact that almost two-thirds of those who did not realize any time benefit from Roger receiver installation still rated it as either “far easier” or “easier” to install the Roger receiver versus attaching an external receiver. A number of these HCPs spontaneously commented that they were accustomed to attaching external receivers through their years of clinical experience, suggesting a possible practice bias with this task. In contrast, there was a significant relationship between the time and rated ease to attach the external receiver, and those who took longer rated it more difficult. Moreover, there was a significant relationship between the difference in time and ease ratings between the two Roger systems, with a larger time difference correlating to a larger change in rated ease.  

The main benefit that HCPs perceived for themselves when installing Roger receivers into hearing aids with RogerDirect was easier and faster Roger fittings. Indeed, the timing results suggest the median time for a binaural Roger fitting using the Roger Installer should be no more than 1 minute 20 seconds. This was far quicker than the time taken for conventional external receiver attachment set-up, without factoring in the need to remove stickers from the contacts in the hearing aid battery compartment. A quicker set-up allows more time for counseling, which was another factor noted by Fabry et al15 as influencing uptake of remote microphone technology. 

The greatest benefit HCPs perceived for their clients when fitted with hearing aids with RogerDirect was the ability to have smaller hearing aids—up to 42% smaller (when comparing Sky M-M with a Sky B-P with Roger 18 receiver attached). Size can affect device retention behind smaller ears, which in turn can influence compliance in younger children.16 It is also well known that children become more conscious about the size of their hearing aids as they grow up,1,17 and cosmetic concerns continue to be a factor for adult acceptance of and satisfaction with hearing aids.18 

Because the hearing aid and Roger receiver are now in a single housing, improved robustness was another key benefit HCPs could see for end-users. This is important as Kochkin19 found device reliability was the 5th-most-important factor driving satisfaction with hearing aids.

Summary and Conclusions

The current study found it is significantly faster and easier to install a Roger receiver into Marvel hearing aids with RogerDirect compared with attaching external Roger receivers to a previous hearing aid model. In fact, a time benefit was demonstrated for three quarters of participants, and almost two thirds of those who didn’t realize any time benefit from installing Roger receivers still rated it as either “far easier” or “easier” versus attaching an external receiver. The most commonly perceived benefits reported by HCPs were easier set-up and use of Roger as well as an overall smaller and more robust hearing aid devices.

References

1. Dillon H. Hearing Aids. 2nd ed. Thieme Medical Publishers; 2012.

2. Mulla I, McCracken W. The use of FM technology for pre-school children with hearing loss. In: A Sound Foundation through Early Amplification 2013: Proceedings of the 6th International Conference; December 9-11, 2013; Chicago, IL. AG:71-76. 

3. Nozza RJ, Wagner EF, Crandell MA. Binaural release from masking for a speech sound in infants, preschoolers, and adults. J Sp Lang Hear Res. 1988;31(2):212-218. 

4. Smaldino J, Crandell C, Brian M, Kreisman A, John AB, Kreisman N. Room acoustics for listeners with normal hearing and hearing impairment. In: Valente M, Hosford-Dunn H, Roeser RJ, eds. Audiology Treatment. 2nd ed. Thieme Medical Publishers;2008:418-451.

5. Shield BM, Dockrell JE. The effects of environmental and classroom noise on the academic attainments of primary school children. J Acoust Soc Am. 2008;123:133.

6. Wake M, Hughes EK, Poulakis Z, Collins C, Rickards FW. Outcomes of children with mild-profound congenital hearing loss at 7 to 8 years: A population study. Ear Hear. 2004;25(1):1-8 

7. Romeo, RR, Leonard JA, Robinson ST, et al. Beyond the 30-million-word gap: Children’s conversational exposure is associated with language-related brain function. Psycholog Sci. 2018;29(5): 700-710. 8. Crowhen D, Turnbull B.

8. Crowhen D, Turnbull B. FOCAS: Family Oriented Communication Assessment and Solutions. Hearing Review. 2018;25(11):20-24.

9. Thibodeau L. Comparison of speech recognition with adaptive digital and FM wireless technology by listeners who use hearing aids. Am J Audiol. 2014;23(2):201-210.

10. Wolfe J, Morais M, Schafer E, et al. Evaluation of speech recognition of cochlear implant recipients using a personal digital adaptive radio frequency system. Am J Audiol. 2013;24(8):714-724.

11. Wolfe J, Morais-Duke M, Jones C, Saoji A. Comparison of wireless microphones. https://www.phonakpro.com/content/dam/phonakpro/gc_hq/en/resources/evidence/field_studies/documents/fsn_Roger_Microphone_Performance_Comparison.pdf. Published January 2015.

12. Park JH. The Effect of Noise in Open-plan and Enclosed Classrooms on Speech Perception for Normal Hearing and Hearing Impaired Children: A Step towards Creating an Acoustically Friendly Flexible Learning Environment [master’s thesis]. Auckland: University of Auckland;2017. 

13. De Ceulaer GD, Bestel J, Mulder HE, Goldbeck F, de Varebeke SPJ, Govaerts PJ. Speech understanding in noise with the Roger Pen, Naida CI Q70 processor, and integrated Roger 17 receiver in a multi-talker network. Eur Arch Otorhinolaryngol. 2016;273:1107-1114. 

14. Lejon AK. Phonak. Significant improvement in speech intelligibility and listening effort in meetings with RogerDirect™ and Roger Table Mic II. Published September 2019. 

15. Fabry D, Mulder H, Dijkstra, E. Acceptance of the wireless microphone as a hearing aid accessory for adults. Hear Jour. 2007; 60(11):32-36 

16. Anderson KL, Madell JR. Improving hearing and hearing aid retention for infants and young children: A practical survey and study of hearing aid retention products. Hearing Review. 2014;21(2):16-20.

17. Northern JL, Downs MP. Hearing in Children. 5th ed. Lippincott Williams & Wilkins (LWW); 2002.

18. McCormack A, Fortnum H. Why do people fitted with hearing aids not wear them? Int J Audiol. 2013;52(5):360-368.

19. Kochkin S. MarkeTrak VIII: Consumer satisfaction with hearing aids is slowly increasing. Hear Jour. 2010;63(1):19-32.   

Correspondence to David Crowhen at: David.Crowhen@phonak.com

Original citation for this article: Crowhen D. A faster way to setting up external recievers: Using Roger and hearing aids with RogerDirect. Hearing Review. 2020;27(7):27-29.