Management of ANSD patients is still a challenge for audiologists. In countries where people can't afford CI, can hearing aids with proper fitting strategies employed benefit individuals with ANSD?
Great question, Prashanth. Hearing aids can mightily assist in various facets of hearing loss and should be pursued, in my thinking, by every person who has a correctable hearing loss. However, it does not get to the root cause of the individual's neuropathy, which might be chronic acidosis, toxicity from medication, uncontrolled blood sugar (diabetes), neck and spinal stenosis, loss of myelin (from a variety of causes, such as long term use of GERD meds and neuroleptic meds), or chronic B-complex deficiency. Whatever the cause, the treatment plan must go beyond the hearing aspect and get to the neurophysiological and metabolic issues, also.
My answer will be relevant to young children who have shown ANSD from birth. Hearing aid(s) should not be fitted until behavioral thresholds of audibility can be obtained. One would most likely not fit a hearing aid for a child with ANSD whose thresholds are nearly normal or severe-profound. Those with mild to moderately severe loss who benefit from hearing aids tend to be the same ones who have cortical auditory evoked potentials. Assuming CAEPs are not clinically readily available in the situation you describe, a quick and dirty way to guess whether a hearing aid might help is to measure even rudimentary speech recognition in each ear separately at (for example) 50dBHL and again at 70-80dBHL. If the child's speech recognition clearly improves at a higher intensity, a hearing aid should be fitted, appropriate to the thresholds of audibility, while visual supports for communication are maintained. Gary Rance's research has suggested that roughly half of children with ANSD can benefit from hearing aids.
As virtually all ANSD patients suffer from very poor critical signal to noise ratios, their communication possibilities can best be enhanced by advanced wireless mcirophone technology, like Roger. Receivers can be attached to hearing aids or cohlear implants, and for those patients with normal or near to normal thresholds, wireless receivers that do not amplify like Roger Focus can improve the SNR without any risk of too high MPO's.
I noticed my comment of more than a year ago was voted down for some reason. Possibly, the reader thought I was downplaying the need for hearing aids in cases of auditory neuropathy. Of course, hearing aids appropriately fitted for a given hearing loss are foundational to any viable auditory rehab program in such cases. My larger point was that the relevant health issues need addressed, also, meaning it becomes an allied professional effort often coordinated by the clinical audiologist or the attending otologist.
Hans made a great point re SNR characterisitics and uncomfortable MPOs of the amplification. Cochlear distortions play into the equation when SNR are not optimal. That's where wireless excels, especially in large area or classroom listening.
Hi with reference to ANSD in children, both Hearing aids and CI showed similar performance in language development (LOCHI study conducted by NAL). However, the important issue is that Hearing Aids for adult ANSD. To my knowledge, there are very few systematic studies conducted on larger population evaluating hearing aid benefit.
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