Measuring consonant identification in nonsense syllables, words, and

Sensorineural hearing loss (SNHL) produces deficits in speech comprehension in noise that primarily are due to impairments in identifying consonants. Here, w e describe the California Syllable Test (CaST) that quant ifies the ident ification of common American English consonants. In experiment I, 16 young sub jects wi th normal hearing iden tified 720 consonant-vowel-consonant (CVC) syll ables in t hree t est sessio ns. Consonants were identified slightly more accurately in words than non sense syl lables, and sm all in teractions were fou nd between the processing of initial and final consonants. Consonant-identification p erformance co rrelated strongly wi th sentence reception thresholds (SeR Ts) meas ured with both the Hearing in Noise Test and QuickSIN (Etymotic Research; Elk Grove Village, Illinois). At SeRTs, subjects with normal hearing could i dentify 32 .5% of consonants in i solated CVCs. In experiment II, a patient with moderate SNHL showed l arge elevations in con sonant-identification thres holds and smaller elevations in SeRTs. At SeRT levels, the patient could identify only 12 .5% of consonants in isolat ed CVCs, indicating that sentence co mprehension relied d isproportionately on vo wel cues and sem antic co nstraints. Conson ant-profile analysis revealed d isproportional i mpairments i n id entifying con sonants depend ent o n hig h-frequency acou stic cues. Conson ant confusion analysis revealed a reorganization of consonant perception. The CaST is a promising tool for evaluating consonantspecific processing deficits in patients with hearing impairment.