Cochlear Implant (CI) listeners can do well when attending to speech in
quiet, yet challenging listening situations are more problematic. Previous
studies have shown that fluctuations in the noise do not yield better speech
recognition scores for CI listeners as they can do for normal hearing (NH)
listeners. The aim of this experiment was to investigate the ability of
simulated CI listeners in a prosodic task, where F0 Just Noticeable
Differences (JND) were measured in modulated and stationary background
noise.

A nonsense sentence was created from a recording with durations and
overall contour derived from non-scripted Danish speech. The F0 temporal
midpoint of the initial syllable was varied stepwise in semitones.
Competing signals of modulated white noise and speech shaped noise at 0
dB and 12 dB SNR, were added to the tokens prior to 8-channel noiseexcited
vocoder processing. Stimuli were presented diotically to 8 NH
listeners in a 2AFC task. A question/statement identification experiment
was also performed. Results from the JND experiment indicate a significant
noise effect for the modulated noise condition at the lower SNR.