Cochlear Implants
by Terry Zwolan, PhD

What’s new with the MSTB-3?

April 25, 2024
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The Minimum Speech Test Battery, Version 3 (MSTB-3) is an updated and streamlined test battery designed for adult cochlear implantation. Developed by the Institute of Cochlear Implant Training (ICIT), this essential tool serves two main purposes:

Pre-operative determination of candidacy: Clinicians use the MSTB-3 to assess whether a patient is a suitable candidate for cochlear implant (CI) surgery.

Post-operative assessment of cochlear implant performance: After implantation, the MSTB-3 helps evaluate how well the cochlear implant is functioning in adult recipients.

Here are the key points of this article and learning outcomes for clinicians:

  • Understanding candidacy assessment for cochlear implant surgery using the new MSTB-3
  • Understanding post-operative assessment and evaluation using the new MSTB-3
  • Understanding the broader applicability of MSTB-3

A brief history of the MSTB…

The first version of the Minimum Speech Test Battery (MSTB) was introduced in 1996. It was later updated in 2011 to include the use of AzBio sentences1, as HINT sentences2 often resulted in ceiling effects when patients were tested in quiet. These early versions of the MSTB were readily adopted and widely used by clinicians for years.

Fast forward to 2022, when it was determined that the way we care for patients with cochlear implants had advanced significantly enough that an update to this test battery was needed. The revision was spearheaded by the ICIT, who recruited a group of experienced professionals to revise and update this classic test battery. The MSTB-3 team set out with several objectives in mind, resulting in the following updates:

  • Electronic format for easier access to materials
  • Comprehensive and streamlined testing for evaluating candidacy and post-operative performance
  • Clear protocols so that clinicians receive defined guidelines
  • Evidence-based recommendations
  • Supplemental Information including patient questionnaires and cognitive screening tools

Detailed information about the MSTB-3 may also be found on the MSTB-3 website. This website not only provides clinicians with the ability to download test materials but also provides response forms, the MSTB-3 manual, patient questionnaires, test protocols, and so much more. For this article, we’d like to highlight some of the new and/or revised features of the MSTB-3.

The MSTB-3 Test Battery

The previous version of the MSTB provided a recommended test protocol as well as a reduced test battery that could be used if needed. This version of the MSTB3 does the opposite; it begins with a streamlined protocol, and suggests additional tests be administered only if supplemental information is needed to determine CI candidacy or to properly evaluate post-operative performance. 

This streamlined battery recommends aided speech recognition testing be preceded by unaided audiometric testing and verification of hearing aids to ensure that candidacy decisions are based on the patient’s “best aided” condition, which the MSTB-3 defines as “testing using a hearing aid that has been optimized for hearing loss in the ear to be implanted.” Speech recognition testing begins with administration of CNC Monosyllabic Words with each ear in the “best aided” condition to determine if one, both, or neither ear meets the clinic’s predetermined CNC score for a cochlear implant. Subsequent testing involves administration of AzBio sentences in the “best aided” condition where testing focuses on the ear to be treated. Importantly, sentence scores provide additional information for candidacy decisions, and are often used to determine if the patient qualifies for insurance coverage since many insurers specify a sentence score that must be met to qualify for a CI. Finally, the MSTB3 recommends clinicians consider evaluating the patient’s speech recognition skills in their “Everyday Listening Condition,” which involves testing with the optimized hearing configuration the patient uses in their everyday listening. This typically varies from patient to patient and may include bilateral hearing aids, unilateral hearing aid, or a bilateral unaided/unoccluded situation, depending on the configuration of their hearing loss.

Patient reported outcome measures (PROMs) are then administered to collect additional information regarding areas of listening that provide particular challenges for the patient. If the clinician determines the patient is an appropriate candidate for a CI, they are referred on for medical evaluation. The PROMs recommended by the MSTB-3 include the CI-QOL 10 Global3 and the SSQ-124. Links to both questionnaires are provided on the MSTB-3 website. 

Here is a breakdown of the key points from the MSTB-3 recommendations:

  1. Speech Recognition Testing:
    1. Unaided audiometric testing to establish the patient’s baseline hearing.
    1. Aided speech recognition using a hearing aid optimized for the ear to be implanted (referred to as the “best aided” condition).
      1. CNC Monosyllabic Words: Administered in the “best aided” condition for each ear.
      1. AzBio Sentences: Also administered in the “best aided” condition, focusing on the ear to be treated.
  2. Everyday Listening Condition:
    1. This involves testing with the optimized hearing configuration the patient uses regularly.
    1. The specific configuration varies (e.g., bilateral hearing aids, unilateral hearing aid, or unaided) based on the patient’s hearing loss.
  3. Patient-Reported Outcome Measures (PROMs):
    1. The recommended PROMs include CI-QOL 10 Global and SSQ-12.

Protocol for patients with Single-Sided Deafness (SSD)

In addition to the test protocol described above, the MSTB-3 provides a recommended candidacy protocol for use with patients with SSD. This test battery is similar to the battery used with traditional candidates, but additionally includes more difficult signal-to-noise ratios. Although indications for SSD often base decisions on CNC scores, the MSTB-3 recommends sentence testing with spatially separated noise to replicate the difficulties experienced by such listeners. Data obtained from such testing often provides additional support for candidacy decisions and may be used to support requests for coverage by the patient’s insurer. 

Cognitive Screening

Unlike previous versions, the MSTB-3 manual provides a literature review regarding cognitive evaluation considerations. Although the MSTB-3 does not specifically recommend the completion of a cognitive screener for all adult patients, decisions about such a screener should be left to the discretion of the clinician. The MSTB-3 does recommend that clinicians should be adequately trained before administering any type of cognitive screener, and that tools should be selected based on validity, specificity and sensitivity to mild cognitive impairment. Importantly, the MSTB-3 states that results of a cognitive screener should not be used to exclude a patient from cochlear implant candidacy.

Report Templates

Lastly, to further support continuity of care across clinicians, the MSTB-3 provides sample report templates for pre-operative determination of candidacy, post-operative programming, and an “After Visit Summary” that can be given to patients to ensure they are informed of the results of the appointment(s). 

Summary

In summary, the MSTB-3 provides a wealth of information that can be used by clinicians to guide their decision-making as they evaluate a patient’s candidacy for a cochlear implant and as they evaluate post-operative performance with a CI. The team that led development of the MSTB-3 is hopeful the protocols and test materials will increase consistency among clinicians regarding test procedures being used. Importantly, the MSTB-3 provides an important opportunity for other areas of audiology to utilize the MSTB-3 resources to improve the care they provide. The patient reported outcome measures are highly appropriate for all patients with hearing loss, and do not only apply to patients with CIs. The discussion about cognitive screening is also applicable to all patients with hearing loss.  Importantly, the MSTB-3 provides downloads of the CNC Monosyllabic Words Test, which could be used by clinicians to evaluate speech recognition over time with hearing aids. Wouldn’t it be great for patients if a CNC score followed them throughout their hearing journey, and we were able to track, over time, how a patient understands words when using appropriate hearing technology? Knowledge of a patient’s aided word recognition would not only serve to enhance counseling but could also be used to identify patients who may be in need of different technology. For example, a CNC score could help determine when the time is right to transition from an over-the-counter hearing aid to a more prescriptive fitting, or when it’s time to transition from a prescription hearing aid to a cochlear implant. It’s exciting to think that this battery could help more patients than just those who use cochlear implants. 

  1. Spahr AJ, Dorman MF. Performance of subjects fit with the Advanced Bionics CII and Nucleus 3G cochlear implant devices. Arch Otolaryngol Head Neck Surg. May 2004;130(5):624-8. doi:10.1001/archotol.130.5.624130/5/624
  2. Nilsson M, Soli SD, Sullivan JA. Development of the Hearing in Noise Test for the measurement of speech reception thresholds in quiet and in noise. J Acoust Soc. Am. 1994 Feb;95(2):1085–1099. 
  3. McRackan TR, Hand BN, Velozo CA, Dubno JR. Validity and reliability of the Cochlear Implant Quality of Life (CIQOL)-35 Profile and CIQOL-10 Global instruments in comparison to legacy instruments. Ear and Hearing. Jul-Aug 2021;42(4):896-908. doi:10.1097/Aud.0000000000001022
  4. Noble W, Jensen NS, Naylor G, Bhullar N, Akeroyd MA. A short form of the Speech, Spatial and Qualities of Hearing scale suitable for clinical use: the SSQ12. Int J Audiol. Jun 2013;52(6):409-12. doi:10.3109/14992027.2013.781278

Acknowledgements 

The MSTB-3 team included Camille Dunn and Terry Zwolan (co-leads), Thomas Balkany and Heather Strader (ICIT), and the following content experts: Allison Biever, Rene’ Gifford, Melissa Hall, Heidi Hill, Meredith Holcomb, English King, Jan Larky, Regina Presley, Meaghan Reed, William Shapiro, Sarah Sydlowski, and Jace Wolfe.  Financial support for development of the MSTB-3 was provided by Advanced Bionics, Cochlear Americas, and MED-EL. 

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Developing innovations with a proven track record of quality

September 27, 2019

By Wade Colburn, Product Manager – Cochlear Implants

Cochlear is committed to the quality of our products and how these products advance hearing performance and quality of life for those affected by hearing loss. With a long-standing track record of reliable implants and durable sound processors2,we focus on delivering quality hearing solutions to meet patient needs.

Since 1982 when Rod Saunders became the first recipient of the Nucleus cochlear implant system3, Cochlear has concentrated on implant and sound processor innovations.  Here’s a glimpse of these innovations over time:

Implant Innovations:

Over the years, implants have improved in many ways, with notable innovations including:

  • Creation of a wide range of electrode variants for varying patient anatomy including the development of perimodiolar electrode arrays with proven performance benefits4,5,6
  • Development of thin and discreet implants reducing the need to drill and improving patient aesthetics
  • Design of an implant with a removable magnet with access to MRI for over 20 years*
  • Enhancement of the design elements and shape to reduce biofilm formation

However, while innovation has been a key focus area, the reliability of the implant over time remains one of the most important features of the Nucleus implant.  But this is nothing new for Cochlear – as those implanted in 1988 with our original implant technology are still able to benefit from our current sound processor offerings and innovations. Yet our commitment to quality means we will continue working to improve the lifespan of each implant generation . We have strived to improve the lifespan of each implant generation so that someone that was implanted in 1988 can still benefit from that original implant technology paired with today’s sound processors.

Processor Innovations:

Sound processor technology has also been transformed over time.  Key innovations of Cochlear sound processors include:

  • Automaticity enhanced sound processing, driving hearing improvement with scene classification and microphone directionality 7
  • Transitioning from body-worn sound processors to the smallest behind-the-ear and off-the-ear sound processors8
  • Chip technologies driving improvement in battery life9, targeted for all-day hearing in a connected world.
  • Direct connectivity of processor to iPhone® and Android™ phones10
  • Datalogs to drive evidence-based clinical decision making
  • Empowerment of patients to monitor and control their device between appointments with the Nucleus Smart App on their smartphone
  • Processors that are water resistant with adventure-proof accessories for hearing whether wet, dry or in between.±

Quite remarkably, Cochlear has designed solutions that make living with a cochlear implant easier, while still maintaining a durable, quality product.  The creation of smaller, smarter and more efficient sound processors has allowed Cochlear to push the cochlear implant industry into a new era. Cochlear promises high quality upgrades that impact performance and lifestyle through backwards compatibility availability.

As the most implanted cochlear implant system with over 395,000 registered systems worldwide2, Cochlear has driven the industry forward with innovations without sacrificing quality.

Historically in the cochlear implant industry, quality has primarily only been measured as implant reliability and all other assessments of quality have been subjective. Reliability reporting has historically been reported based on the European Consensus Statement, but not all manufacturers maintained compliance. 

Cochlear is now excited to also report in compliance with a new standard for the cochlear implant industry – ANSI/AAMI CI86: 2017 Cochlear implant systems: requirements for safety, functional verification, labeling and reliability reporting.  In accordance with this standard, quality of both implants and processors can be assessed. 

For implants, our new reporting measurement will be reported as the Cumulative Removal Percentage (CRP).  This new measurement will look at all implants that have been removed for any reason, including infection. The Profile series, with over 70,000 devices implanted, has a CRP of 1.21%, meaning that 98.79% of implants remain working within 5 years.

For the first time ever, processor reliability is being reported as Failed Component Return Rate (FCRR), which is a percentage calculated by comparing the number of faulty processors returned within a month compared to the cumulative sales of the sound processor over a period of up to 24 months. For Nucleus 7, the average FCRR is .2% over 16 months compared to Nucleus 6, with an average FCRR of .8% average over 24 months.

Check out this example of how the FCRR is calculated (not real numbers):

To learn more about reliability reporting and download our latest reliability report in compliance with ANSI/AAMI CI86.  For more information on the difference between the European Consensus Report and ANSI/AAMI CI86, click here.

About the author: Wade is the Product Manager for Cochlear Implant product portfolio within Cochlear Americas.  Wade’s responsibilities include product positioning and messaging, life-cycle management, new product launches and surgical support and training. Wade has recently joined Cochlear, but comes from an engineering background with the medical device field, including previous otology experience. 

*Cochlear has had MRI access dating back to 1997.  With removal of the magnets, Freedom and Profile series implants are approved for 1.5T and 3.0T MRI’s. The latest implant generation, Profile Plus, allows for 1.5 T and 3.0 T without magnet removal or compression.

±The Nucleus 7 Sound Processor with Aqua+ is water resistant to level IP68 of the International Standard IEC60529. This water protection rating means that the sound processor with the Aqua+ can be continuously submerged under water to a depth of 3 m (9 ft and 9 in) for up to 2 hours. This water protection only applies when you use a Cochlear Standard Rechargeable Battery Module or Cochlear Compact Rechargeable Battery Module.

References:

  1. D1593476. Cochlear Nucleus Implant Reliability Report. Volume 17. December 2018.
  2. D1599672. Cochlear Nucleus Reliability Report (Reporting to ANSI/AAMI CI86 Standard). Volume 1. September 2019.
  3. https://www.cochlear.com/intl/about/company-information/history-of-innovation
  4. Hughes, ML, Abbas, PJ. Electrophysiological channel interaction, electrode pitch ranking, and behavioral threshold in straight versus perimodiolar cochlear implant electrode arrays. J Acoustic Soc Am. 2006; 119(3):1538-47.
  5. Cohen L., Richardson L., Saunders E., Cowan R. Spatial spread of neural excitation in cochlear implant recipients: comparison of improved ECAP method and psychophysical forward masking. Hearing Research. 2003; 179 (1-2):72-87.
  6. Holden LK, Finley CC, Firszt JB, Holden TA, Brenner C, Potts LG, et al. Factors affecting open-set word recognition in adults with cochlear implants. Ear Hear. 2013; 34(3):342-60
  7. Cochlear Limited. D1296247. CLTD 5620 Clinical Evaluation of Nucleus 7 Cochlear Implant System. 2017, Sept; Data on file
  8.  Cochlear Limited. D1190805. CP1000 Processor Size Comparison. 2019, Apr; Data on file
  9. Cochlear Limited. D1140877. Battery Life and Power Consumption Comparison between CP1000, CP900 Series and CP810 Sound Processors. 2017, Sept; Data on file.
  10. Compatibility can be found here: hhtp://www.cochlear.com/compatibility

The Cochlear Nucleus 7 Sound Processor is compatible with iPhone, iPad and iPod touch. Apple, the Apple logo, FaceTime, Made for iPad logo, Made for iPhone logo, Made for iPod logo, iPhone, iPad Pro, iPad Air, iPad mini, iPad and iPod touch are trademarks of Apple Inc., registered in the U.S. and other countries.

App Store is a service mark of Apple Inc., registered in the U.S. and other countries.

Android and Google Play are registered trademarks of Google Inc. The Android robot is reproduced or modified from work created and shared by Google and used according to terms described in the Creative Commons 3.0 Attribution License.

The Cochlear Nucleus Smart App is available on App Store and Google Play. For complete smartphone compatibility information, please visit www.cochlear.com/compatibility.

cochlear next

Surgical Outcomes of CI532 Clinical Study: Does electrode placement impact hearing performance?

July 8, 2019

In the spring of this year, sixty-five otology and audiology professionals came together for Cochlear NEXT – a program focused on learning and discussion regarding Cochlear’s CI532 Clinical Study and the respective implications of this emerging and impactful data.

The following information reviews the primary talking points and output from the day’s first topic.

 Surgical Outcomes of CI532 Clinical Study: Does electrode placement impact performance?

Presenters:

  • Wade Colburn, Biomedical Engineer and Product Manager, Cochlear Implants, Cochlear Americas
  • Jonathan McJunkin, MD, Surgeon and CI532 study Investigator, Washington University in St. Louis

A review of published (non-CI532) evidence demonstrates prevailing thought regarding the relationship between electrode placement and hearing performance, prior to the CI532 study:

  • Pre-curved arrays may be less likely to be placed in scala tympani 1
  • ERW and RW may lead to more consistent scala tympani placement 1, 2, 3
  • Electrode placement within scala tympani significantly impacts patient performance 4

When asked in a pre-event survey, only 66% of surgeons agreed that consistent placement in the scala tympani is as likely to occur with CI532 as it is with lateral wall electrode arrays. There was also some difference of opinion on the importance of electrode placement, with only 64% of surgeons agreeing that proximity of the array to the modiolus has an impact on hearing performance.

However, CI532 clinical study results demonstrate that rates of scala tympani placement of the CI532 electrode are on par with previously cited studies using lateral wall electrodes, with 89% of electrodes being successfully inserted in the scala tympani 5. A mean wrapping factor of 59.6% – which describes the proximity of the electrode to the modiolus – further illustrates the consistency of surgical outcomes using the Slim Modiolar electrode5.  For reference, Holden et al. showed that patients with a wrapping factor closer to 60% positively correlated with better hearing performance6.

 Following presentation of the data and dynamic group discussions, participant consensus shifted considerably according to the post-event survey, with now 86% of surgeons agreeing that consistent placement in the scala tympani is as likely to occur with CI532 as it is with lateral wall electrode arrays. Further, 82% supported that proximity of the electrode array to the modiolus has an impact on hearing performance.

Additional discussion focused on the topic of surgical approach, as one of the key design goals of CI532 was an electrode that is indicated for round window (RW), extended round window (ERW), and cochleostomy – allowing surgeons to utilize flexibility and preference when determining surgical technique.  Live polling during the NEXT program demonstrated a strong preference for the RW and ERW approaches confirming a perceived industry shift away from cochleostomy as surgeons strive to limit structural trauma caused by implant insertion.

In summary, a review of current and historical data, combined with dynamic large and small group discussions, drove a measurable change in participant perception regarding the positive correlation between electrode placement and hearing performance.

Don’t miss the next installment of our Cochlear NEXT proceedings: Clinical Outcomes of CI532 Clinical Study: A new clinical care approach. Subscribe to our ProNews Blog using the panel to the left to ensure you receive future updates!

 

© Cochlear Limited 2019. All rights reserved. Hear now. And always and other trademarks and registered trademarks are the property of Cochlear Limited or Cochlear Bone Anchored Solutions AB. The names of actual companies and products mentioned herein may be the trademarks of their respective owners.

 References

  1. O’Connell BP, Hunter JB, Wanna GB. The importance of electrode location in cochlear implantation. Laryngoscope Investig Otolaryngol. 2016;1(6):169–174. Published 2016 Nov 29. doi:10.1002/lio2.42
  2. Wanna GB, Noble JH, Carlson ML, et al. Impact of electrode design and surgical approach on scalar location and cochlear implant outcomes. Laryngoscope. 2014;124 Suppl 6(0 6):S1–S7. doi:10.1002/lary.24728
  3. Briggs RJ1, Tykocinski M, Stidham K, Roberson JB. Cochleostomy site: implications for electrode placement and hearing preservation. Acta Otolaryngol. 2005 Aug;125(8):870-6.
  4. Shaul C, Dragovic AS, Stringer AK, O’Leary SJ, Briggs RJ. Scalar localization of peri-modiolar electrodes and speech perception outcomes. J Laryngol Otol 2018; 1- https://doi.org/10.1017/S0022215118001871
  5. Preliminary Data on File: US Multicenter CI532 Study. 2018.
  6. Holden et al. Factors affecting open-set word recognition in adults with cochlear implants. Ear and Hearing. 2013; 34:342-60. https://www.ncbi.nlm.nih.gov/pubmed/23348845

 

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This material is intended for health professionals. If you are a consumer, please seek advice from your health professional about treatments for hearing loss. Outcomes may vary, and your health professional will advise you about the factors which could affect your outcome. Always read the instructions for use. Not all products are available in all countries. Please contact your local Cochlear representative for product information.

 

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