Auditory Brain Training & Adults Who Use Cochlear Implants: A Little Philosophizing & Some Interesting Data



By Nancy Tye-Murray, Ph.D. and Brent Spehar, Ph.D.

The term auditory training is often used to describe a broad array of training programs, many of which differ from one another in philosophical approach and training activities. For example, some programs emphasize recognition of nonsense syllables while others emphasize words or sentences. Some gamify training while others present rote drill. Not surprisingly, recent mega-analyses that have been performed about auditory training have yielded nebulous conclusions about its benefits because, in essence, apples are being lumped together with oranges. In this report, we make the case that cochlear implant centers often do not provide auditory training to their adult cochlear implant recipients because of ambiguity about its effectiveness. A new approach, auditory brain training, which is meaning-based and gamified, is described and results are presented for 15 experienced cochlear implant users. The participants showed improved speech discrimination and sentence recognition after receiving 12 hours of training.

When hearing healthcare professionals say “auditory training” or when they see the term in a research article, they often believe that the term always refers to a similar training experience. “They’re teaching people how to maximize their residual hearing, right?” they might muse, or, “Listening therapy for the ears, like physical therapy for a bum knee.”

The problem with this kind of assumption is that there is no universal agreement on what constitutes auditory training and different training curricula can lead to different results. For instance, Sweetow and Palmer (2005) surveyed the literature to answer the following question: “Is there evidence of improvement in communication skills through individual auditory training in an adult hearing –impaired population?” (p. 494). Not surprisingly, the answer was equivocal. For the six research studies that met the authors’ criteria of methodological rigor, four reported that auditory training enhanced listening performance, one did not, and one reported mixed results. All six studies had a different instantiation of auditory training. Similarly, Henshaw and Ferguson (2013) performed a meta-analysis of the benefits of computerized auditory training. Based on the authors’ examination of thirteen research studies that met their inclusion criteria of good experimental design, they concluded that overall, results were not always consistent or robust but it appeared that training results in modest gains in speech recognition.

Because there are many different philosophies about how to structure auditory training, its effectiveness should be considered within the context of what comprises the training experience. For example, some curricula focus on phoneme-based, nonsense syllable training (e.g., aba and ata, Moore, Rosenberg, & Coleman, 2005), with the assumption that once a patient acquires the “building blocks” of language, this learning will lead to better recognition of words and sentences. Other curricula emphasize meaningful speech units such as words and sentences. For example, Humes et al. (2009) advocate teaching patients to recognize the most frequently used words of the English language, as they comprise the bulk of everyday conversation. Boothroyd’s approach (2008) entails presenting sentences that are topically related, such as sentences pertaining to the topics of food or work.

The inconsistent findings about the effectiveness of auditory training, and the ambiguity about what auditory training means, probably account in part for why formal auditory training is often not offered on a routine basis to adults who have just received a cochlear implant. It is seemingly impossible to make a blanket statement about whether or not patients will receive benefit, and because evidence-based practice is the gold standard for many cochlear implant centers, auditory training is not offered in a formal or systematic way.

clEAR (customized learning: Exercises for Aural Rehabilitation) provides auditory brain training to people who have hearing loss via computer games that are accessed through the web (www.clearworks4ears.com). The word brain is inserted between the words auditory and training because clEAR not only provides training on word discrimination, the most frequent words of the language, and sentence and discourse comprehension, but also provides training for those cognitive skills that are needed to recognize any connected speech. These cognitive skills are auditory processing speed, auditory working memory, and auditory attention. The clEAR games rest on two fundamental principles: 1) training must engage patients’ attention in order for learning to occur and 2) training must be meaningful.

The rationale for gamified training is presented in Table 1. In a nutshell, in order for the adult brain to learn new perceptual skills, it must be aroused by and engaged in the learning process. Rote discrimination tasks, such as indicating trial after trial whether two nonsense syllables are the “same” or “different”, as often happens in traditional auditory training, likely does not engage the brain in a way that will promote perceptual learning and indeed, might lead to a brain state that is soporific.
Table 1: Why Auditory Brain Training That is “Gamified” Is More Likely to be Effective than Ordinary Auditory Training for People Who Have Hearing Loss
  • Playing video games is pleasurable.
  • Pleasant activities cause the brain to increase production of dopamine, which is a neurotransmitter that acts as a “messenger” between brain cells.
  • Research has shown that playing video games increases production of dopamine.
  • Increased dopamine levels enhance neural plasticity.
  • Enhanced neural plasticity allows for greater perceptual learning.
  • Hence, adults with hearing loss have better potential for learning to use their residual hearing when playing auditory brain training games than when engaging in rote auditory training tasks.
The rationale for meaningful training is founded on principles of learning and memory and includes exclusive use of meaning-based training. Meaning-based training is critical because to communicate successfully in the real world, adults with cochlear implants, like learners of any novel language, must not only attend to the formal properties of sounds but must do so while attending to the meaning or communicative content that the sounds convey. Moreover, there is evidence that phoneme perception and word perception are uncorrelated (Sommers et al., 2005), making it unlikely that even successful form-only training on nonsense syllables will lead to generalizable gains in word perception. Evidence for the superiority of meaning-based training has a long history within the field of second language acquisition (e.g., Savignon, 1972).

To assess the effectiveness of gamified, meaning-based auditory brain training for experienced adult cochlear implant (CI) users, we provided 12 one-hour training sessions to 15 CI users (see Table 2). We stipulated that they be experienced because we did not want to confound the effects of auditory brain training with the natural adjustment period with a new listening device.
Table 2. Information About the participants
Participants 15 CI users, 7 female, average age = 59 years (SD=17.6)
Average duration of CI use 5.5 years (SD=5.2)
Device type 10=Cochlear Corp.; 5=Advanced Bionics; 9 use HA in non-implanted ear
Training procedures Twelve 1 hour training sessions, twice per week using beta versions of the clEAR computer auditory brain training games, occurring at the Tye-Murray lab

On a four-choice word discrimination test, 10 of the 15 participants showed improvement in their ability to discriminate the speech of a talker with whom they did not train (Figure 1). On a “Build-a-Sentence” test, which assessed closed-set sentence recognition using words displayed in a matrix, eight of 15 participants showed improvement in their ability to recognize sentences (Figure 2). Finally, on a test of perceptual effort, which measures perceptual effort with a memory task, results were variable and inconclusive (Figure 3).
Figure 1. Results From a 4-Choice Word Discrimination Test

The participant hears two words (e.g., cup-pup and then has to pick the correct illustration from four pictures, one of which shows two cups, one which shows two pups, one which shows a cup by a pup, and one which shows a pup by a cup.

Figure 2. Results From the Build-a-Sentence Test

The participant hears a sentence that is a a carrier phrase, The ____ and the ____ see the ____ and the _____, and then must fill in the target words from a matrix of 36 candidates.
Figure 3. Results From the Test of Perceptual Effort

A variant of an N-back memory task, participants hearing a running list of words and are asked to update continually the three most recently presented words.

Participants also completed questionnaires at the end of training and 6-months post-training. Results are presented in Table 3. Overall, the subjective impression of auditory brain training was very favorable.
Table 3: Responses to Questionnaires Administered Immediately After Auditory Brain Training and then 6 Months Later
1 Please indicate how much you believe that you improved in your ability to understand spoken language as a result of having participated in training on a scale from 1 through 7, where 1 = “very little” and 7 = “very much”.
Average = 4 (SD = 1.2)
2 To what extent has participating in this program improved your self-confidence in engaging in conversation with casual acquaintances or strangers on a scale from 1 through 7, where 1 = “very little” and 7 = “very much”?
Average = 4 (SD = 1.6)
3 To what extent has participating in this program improved your self-confidence in engaging in conversation with family members or close friends on a scale from 1 through 7?
Average = 4 (SD = 1.8)
4 Please indicate how much you enjoyed participating in this program on a scale from 1 through 7?
Average = 6 (SD = 1.1)
5 Was the program worth your time? (asked at 6 months post training)
100% said yes
6 Would you do the program again? (asked at 6 months post training)
100% said yes
7 Would you recommend the program to a friend? (asked at 6 months post training)
100% said yes


These findings are remarkable because, with the exception of perceptual effort, auditory brain training improved objective and subjective measures of performance for the majority of the participants. In our next round of research, we will providing clEAR to new CI recipients (i.e., less than 6 months of experience). It is quite possible that gamified, meaning-based auditory brain training that utilizes the kinds of training activities described here will accelerate the natural learning curve that occurs with receipt of a new cochlear implant and leads to a higher level of speech recognition performance than would have occurred otherwise.    
Nancy Tye-Murray, Ph.D. & Brent Spehar, Ph.D., Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO. The authors can be contacted at support@clearworks4ears.com.

Acknowledgements and Disclosures: This research was supported by NIH DC008964. The authors are co-founders of clEAR (customized learning: Exercises for Aural Rehabilitation) and have ownership interest.
References
Boothroyd, A. (2008). CasperSent: A program for computer-assisted speech perception testing and training at the sentence level. Journal of the Academy of Rehabilitative Audiology, 41, 30-50.

Henshaw, H., & Ferguson, M. A. (2013). Efficacy of individual computer-based auditory training for people with hearing loss: a systematic review of the evidence. Plos One 8, e62836.doi:10.1371/journal.pone.0062836

Humes, L. E., Burk, M. H., Strauser, L. E., & Kinney, D. L. (2009). Development and efficacy of a frequent-word auditory training protocol for older adults with impaired hearing. Ear and hearing, 30(5), 6613.

Moore, D.R., Rosenberg, J.F., & Coleman, J.S. (2005). Discrimination training of phonemic contrasts enhances phonological processing in mainstream school children. Brain and Language, 94(1), 72-85.

Savignon, S.J. (1972) Communicative competence: An experiment in language teaching. (Vol. 12). Marcel Didier.

Sommers, M. S., Tye-Murray, N., & Spehar, B. (2005). Auditory-visual speech perception and auditory-visual enhancement in normal-hearing younger and older adults. Ear and Hearing, 26(3), 263-275.

Sweetow, R. W., & Palmer, C.V. (2005). Efficacy of individual auditory training in adults: A systematic review of the evidence. Journal of the American Academy of Audiology, 16(7), 494-504.