Three perceptually distinct maskers can be equated for masking effectiveness in CI users

Evidence

The sentences were presented in three different types of masker, as in Oxenham and Kreft ( 2014 ); see Fig. 2 . The first was a Gaussian noise, spectrally shaped to match the long-term spectrum of the target speech. The second was comprised of 16 pure tones, approximately evenly spaced on a logarithmic frequency scale from 333 to 6665 Hz, corresponding to the center frequencies on a standard CI map for Advanced Bionics. The amplitudes of the tones were selected to produce the same long-term output of a 16-channel vocoder as the target speech (or Gaussian noise masker), assuming the same center frequencies. The third was comprised of the same 16 tones, but each tone was modulated independently with the temporal envelope of a noise masker, bandpass filtered using a vocoder filter with the same center frequency as the tone carrier. These three maskers produced equal amounts of speech masking in the CI users tested by Oxenham and Kreft ( 2014 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 2174