Effect of Chronological Age on Pulse Rate Discrimination in Adult Cochlear-Implant Users.
Kelly C Johnson, Zilong Xie, Maureen J Shader and 2 others
PMID 34028313WHAT IT FOUND
Older cochlear implant users struggled more than younger ones to tell pulse rates apart, but only at high rates like 500 pps.
At lower rates, age made no difference. Steeper nerve response slopes did not predict better discrimination.
Key findings
01Age significantly interacted with baseline rate, with older participants performing worse than younger ones at high rates like 500 pps but better at low rates like 100 pps.
02Steeper ECAP amplitude growth function slopes were associated with poorer, not better, rate discrimination at the 300 pps reference condition.
03Pulse rate discrimination ability decreased as stimulation rate increased, regardless of age.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The sample size was small, with only 20 participants. Chronological age was highly correlated with age at onset of deafness, making it difficult to separate the effects of aging from the effects of long-term deafness. The study used a fixed 35% rate change, so it did not determine the precise threshold for discrimination differences between age groups. Participants may have used loudness cues rather than pitch cues to complete the discrimination task in some trials. One younger participant scored below the cutoff for cognitive impairment on the MoCA but was retained in the analysis.
Declared interests
The authors declared no potential conflicts of interest. The study was funded by the National Institute on Aging and the National Institute on Deafness and Other Communication Disorders.
The easy way to misread this
Do not conclude that age alone causes a general decline in temporal processing. The effect of age was dependent on the stimulation rate, with older users performing better at low rates and worse at high rates. Additionally, do not interpret steeper ECAP slopes as a sign of better temporal processing ability, as they were associated with poorer performance in this study.