The role of intensity upon pitch perception in cochlear implant recipients.
OBJECTIVE
Pitch plays a key role in the perception of speech and music, the recognition of a speaker's voice, and in analyzing complex auditory patterns. To date, little consideration has been given to the influence of stimulation level on pitch perception. The aim of this study was to investigate the impact of a sound's intensity on pitch perception in cochlear implant recipients using monopolar stimulation.


METHODS
Thirteen patients with an average implant use of 4.13 years took part in this study. All patients were implanted with MedEl Combi 40/40+ cochlear implants.


METHODS
In the first part of the study, we performed a pitch ranking procedure to confirm that all patients were able to judge pitch changes. Using a visual scale, study participants were then asked to compare the pitch of an intensity-constant reference tone with the pitch of a test tone of varying intensity.


RESULTS
Eleven (85%) patients were found to perceive a clear change in pitch with changing stimulus intensity. Statistical analysis showed a strong positive correlation in 10 patients (correlation coefficients between 0.99 and 0.71) and a strong negative correlation in 1 patient (r = -0.92).


CONCLUSIONS
The results suggest that a distinct relationship exists between pitch perception and intensity of the stimulus. To date, speech coding strategies do not support these findings. Nevertheless, we believe that for the optimized most natural perception of sounds, especially music, the described particularities of pitch perception need to be respected, and further investigations on this topic are necessary.
Arnoldner
Christoph
C
Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria.
Kaider
Alexandra
A
Hamzavi
Jafar
J
D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception / Q000502:physiology; D001309:Auditory Threshold / Q000502:physiology; D019929:Cochlear Implantation / Q000379:methods; D003054:Cochlear Implants; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008144:Loudness Perception / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010898:Pitch Perception / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology