A fast method for measuring psychophysical thresholds across the cochlear implant array.

Area of Science:

• Audiology
• Neuroscience
• Biomedical Engineering

Background:

• Cochlear implants (CIs) require accurate threshold measurements for optimal hearing rehabilitation.
• Traditional threshold measurement procedures can be time-consuming.
• Developing rapid and reliable methods is crucial for efficient clinical practice.

Purpose of the Study:

• To propose and evaluate a novel, rapid threshold measurement procedure for cochlear implant users.
• To compare the proposed Bekesy tracking-based method with a traditional adaptive procedure.
• To assess the speed and reliability of the new method.

Main Methods:

• A Bekesy tracking procedure with virtual spectral sweeps using current steering was developed.
• Absolute thresholds for biphasic pulse trains were measured in 15 postlingually deafened adult CI users.
• Thresholds were compared between the new tracking procedure and a traditional forced-choice adaptive procedure under monopolar and quadrupolar stimulation.

Main Results:

• No systematic differences were observed between threshold estimates from the new sweep procedure and the traditional adaptive procedure.
• The new method was approximately four times faster than the traditional procedure for the same number of repetitions.
• Test-retest reliability of the new sweep procedure was slightly poorer compared to the traditional procedure.

Conclusions:

• The proposed rapid threshold measurement procedure demonstrates potential for clinical application due to its significant speed advantage.
• The trade-off between speed and reliability suggests careful consideration for specific clinical scenarios.
• Faster threshold estimation is particularly valuable when combined with focused stimulation techniques in cochlear implant fitting.