Perception of “Elliptical Speech” by an Adult Hearing-Impaired Listener with a Cochlear Implant: Some Preliminary Findings on Coarse-Coding in Speech Perception1

This paper examines the effects of elliptical speech (Miller & Nicely, 1955) on the speech perception performance of an adult hearing-impaired listener with a cochlear implant. A group of 20 normal-hearing adult listeners were used for comparison. Two experiments were carried out using sets of normal and anomalous English sentences. Two versions of each set of sentences were constructed. One version retained normal place of articulation; the other was converted to “elliptical speech” using a procedure in which different places of articulation were all converted to the same alveolar place of articulation. The patient completed a same-different task and a transcription task. The normal-hearing listeners completed the same tasks, but with noise-masking or low-pass filtering used to degrade the signal. In the same-different task, we found that normalhearing listeners under conditions of signal degradation tended to label a sentence with normal place of articulation and its elliptical version as the “same.” The hearing-impaired listener with the cochlear implant also tended to label a sentence with normal place of articulation and its elliptical version as the “same.” Results provide support for Miller and Nicely’s claim that under conditions of signal degradation, the ellipsis can no longer be detected. In the transcription task, however, normal-hearing subjects showed better transcription performance for sentences with normal place of articulation than for “elliptical” speech sentences, which was an unexpected result given our findings in the first experiment. The patient with the cochlear implant also showed better transcription performance for sentences with normal place of articulation than for “elliptical” speech, which was also unexpected. The implications of these findings for how cochlear implant users perceive speech and recognize spoken words are discussed.