The Perception of Ramped Pulse Shapes in Cochlear Implant Users.
Charlotte Amalie Navntoft, David M Landsberger, Tania Rinaldi Barkat and 1 others
PMID 34935552WHAT IT FOUND
Cochlear implant ramped pulses used less charge than standard rectangular pulses at threshold and comfortable loudness, but needed higher peak current.
Rising and declining ramps were not different, and listeners rarely told them apart.
Key findings
01Ramped pulses required less charge than rectangular pulses at detection threshold and at a loudness-balanced comfortable level, but they required a higher peak current amplitude.
02Rising and declining ramped pulses were not reliably different from each other.
03Only one participant could reliably tell equally loud ramped and rectangular pulses apart, and threshold profiles across electrodes were similar.
STILL TO COME
How it was doneWhat they found
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
Only participants with Advanced Bionics implants were tested, and stimulation was delivered directly in a laboratory rather than through a clinical processor. The study did not test speech perception, music, battery life, or real-world device programming. The low starting level for ramped pulses may not have been optimal, which could affect comparisons between rising and declining ramps. The small sample and noisy threshold measurements limit generalisation, and the authors note that statistical power may explain differences between the single-electrode and array-wide results.
Declared interests
The authors declared no potential conflicts of interest. The work was supported by the William Demant Foundation and the Swiss National Science Foundation.
The easy way to misread this
Do not treat ramped pulse shapes as a clinically available or proven improvement in hearing or battery life. This was a laboratory experiment using direct stimulation, and it did not test speech perception or real-world device programming.