Effect of acoustic cues on labeling fricatives and affricates

Previous studies have shown that manipulation of frication amplitude relative to vowel amplitude in the third formant frequency region affects labeling of place of articulation for the fricative contrast /s/-/integral of/ [Hedrick & Ohde, 1993; Stevens, 1985]. The current study examined the influence of this relative amplitude manipulation in conjunction with presentation level, frication duration, and formant transition cues for labeling fricative place of articulation by listeners with normal hearing and listeners with sensorineural hearing loss. Synthetic consonant-vowel (CV) stimuli were used in which the amplitude of the frication relative to vowel onset amplitude in the third formant frequency region was manipulated across a 20 dB range. The listeners with hearing loss appeared to have more difficulty using the formant transition component than the relative amplitude component for the labeling task than most listeners with normal hearing. A second experiment was performed with the same stimuli in which the listeners were given one additional labeling response alternative, the affricate /t integral of/. Results from this experiment showed that listeners with normal hearing gave more /t integral of/ labels as relative amplitude and presentation level increased and frication duration decreased. There was a significant difference between the two groups in the number of affricate responses, as listeners with hearing loss gave fewer /t integral of/ labels.