This study examines optimal conversions of speech sounds to audible electric currents in
cochlear-implant listeners. The speech dynamic range was measured for 20 consonants
and 12 vowels spoken by five female and five male talkers. Even when the maximal root-
mean-square (rms) level was normalized for all phoneme tokens, both broadband and
narrow-band acoustic analyses showed an approximately 50-dB distribution of speech
envelope levels. Phoneme recognition was also obtained in ten CLARION implant users as …