Bimodal Boost

Originally Published by Phonak Audiology Blog:

Bimodal boost | Phonak Audiology Blog – Phonak Pro – life is on

---

Can your brain can make sense of an amplified acoustic signal in one ear and an electronic signal in the opposite ear? This was a frequent question asked to me. I had the same question going into my cochlear implant journey; knowing that I likely would be a bimodal recipient for some time.

As I write this blog, I want to make a disclaimer that each individual has a different journey with the cochlear implant process. I am excited to share my own perception as a prelingually deaf adult who is also an educational audiologist.

Back to the most frequently asked question – Do you think your brain can get used to an acoustic signal in one ear and an electronic signal in the other ear? For me, yes! I am continuously amazed at how the human brain can make sense of dual signals and eventually integrate into understandable speech. Did this happen instantly? Absolutely not. I have had countless mappings, hearing aid adjustments, auditory therapy with an auditory verbal speech therapist, individual listening practice, and courageously experiencing different environments in our vibrant hearing world.

Hearing aid background

In order to understand my perception of bimodal, I think it helps to have a historical perspective of my hearing aid experience. I have always been attached to my hearing aids. When one hearing aid would need to go in for repair, I felt lost. I could feel my anxiety increase in unfamiliar situations. My hearing loss is also a nightmare loss to fit. I have essentially normal hearing from 125-250 Hz, mild loss at 500 Hz, and then severe to profound from 750-8000 Hz. I have the black diamond of ski slope hearing losses. I have always been a user that values lots of analog power (yes, the switch to digital hearing aids was rough!). So basically my hearing aids have been providing a lot of bass sounds over the years and essentially not much usable high frequency access.

Cochlear implant listening

Post activation everything was confusing. My CI sounded likes beeps, chirps, and whistles. I knew that I needed to ‘train my brain’ to figure out what all of these beeps, chirps, and whistles were so I spent dedicated time only listening with my cochlear implant. Each day when I was not in a ‘must hear for work’ situation, I would spend quality time with my CI. In addition, I attended weekly sessions with my auditory verbal therapist doing listening therapy with my CI. On my own, I supplemented in-person therapy by streaming to my CI listening apps and audiobooks. I also had to learn to be still and listen to sounds in my environment and try to make sense of what I was hearing with my CI.

Bimodal experience

As an audiologist and consumer, I know how important it is to keep the neural networks of my right and left auditory brain pathway stimulated. I was dedicated to making the bimodal experience work for me. In the beginning of the CI journey, I knew that I was 100% relying on my Phonak B90 SP behind the ear hearing aid in my right ear as the Naída Q90 CI from Advanced Bionics in my left ear was initially giving me a lot of beeps, chirps, and whistles. Again, I asked the most frequent question – Can the brain integrate an acoustic and electronic signal?

Bimodal switching

One of the fascinating discoveries is recognizing all of the new sounds that were present in my world. In order to really figure out these new discoveries, I found that spending mindful time sitting in various environments helped me process what I was missing and what I was gaining. Switching in the moment between CI alone and HA alone allowed me to recognize what I was missing with my hearing aid and process new discoveries of sounds with my cochlear implant. One perfect example is sitting outside on my back porch. We have a wind chime hanging nearby. With my hearing aid alone, the wind chime does not make a noise, with my CI alone, I am opened up to a new world of sounds. Setting aside this mindful times to allow myself to do bimodal switching (what I like to call this listening experience), I allowed myself to identify sounds, voices, and music and grow new auditory networks to make sense and process this new CI signal.

Bimodal hearing

Finding the balance between CI mapping and hearing aid programming has been a work in progress. With much grit and determination, it is with joy that I share that my bimodal journey has given me new access to a whole new world of sounds and speech understanding. I know that I am not at the end of my hearing journey and there is still much work to be done. At this point in my cochlear implant journey, I have discovered that my brain is bridging the more natural acoustic signal of my residual low frequency hearing and amplified hearing aid benefit with the newly gained mid and high frequency access that my cochlear implant provides. Wow, the brain is quite amazing. I have discovered that each ear alone is not enough but together provide a rich listening experience.

Everyone’s hearing journey is different and there are different factors that can impact the hearing journey. For some individuals the bimodal experience is appropriate. For others, a bilateral experience with cochlear implants may be more beneficial. Empowering yourself as a professional as well as informing your patient of their options is an important part of the hearing journey.

---

Experiential learning tips for the audiologist and bimodal user

1. In person auditory rehabilitation: During the first 6 months of my CI journey, I met with an auditory verbal therapist. Weekly in person sessions helped me stay accountable in my CI listening journey and gave me the confidence to know that I was making progress.
2. Online auditory skills training: Apps and websites like SoundSuccess™ rehabilitation resource, can provide listening practice to reinforce our brain’s ability to perceive and understand spoken language.
3. CI and HA audiologist: Going bimodal meant that I now had 2 different audiologists. Ensure that both the clinical and CI audiologist are working together to ensure that the bimodal experience is successful. There is a growing body of research regarding how a CI and HA can complement each other through programming options.
4. HA and CI compatibility: Phonak and Advanced Bionics are working together to support bimodal listeners through complimentary and compatible hearing technology. Technology is always evolving and when I am eligible for a technology upgrade, I cannot wait to maximize more listening experiences in my bimodal journey.
5. Listening coach: Having someone share what you might be hearing. My husband and my kids became my listening coaches. Encourage your patients to set aside time in different environments to listen quietly and have others describe the different sounds that are happening.
6. Auditory journal: Start a journal of all of the new sounds that you are discovering. Being able to reflect back on the beginning of the journey and at different intervals gives confidence and motivation to keep improving the bimodal experience.
7. Continuous monitoring of unaided and aided for hearing aid performance: At each mapping appointment, testing the hearing aid only benefit with speech is important. My speech discrimination and aided benefit continues to be stable in my right ear. However, if a change is noted, I want to be able to emotionally prepare for a bilateral CI decision.