ABSTRACT
Three studies examined subjects' ability to identify phonetic information from speech spectrograms. In Experiment 1, five students (enrolled in a graduate course in speech communication that included some training in spectrogram reading) were asked to label phonetically spectrograms of five unknown sentences. On the first choice, the students correctly identified about 50% of all the segments and an additional 30% were identified on second and third choices. Experiments 2 and 3 examined the performance of a speech scientist who has had extensive practice in labeling spectrograms. In Experiment 2, the reader labeled 11 spectrograms as quickly as possible in a single pass from left to right. Labeling time decreased with practice from about 12 sec per segment to about 3 sec per segment. Labeling accuracy, about 85% correct including first, second, and third choices, was not correlated with reading time. Experiment 3 explored the reader's ability to name words in a known carrier phrase from spectrograms. On the first trial, 21 of the 25 words were correctly identified with a mean time per segment of about 2.3 sec. The implications of the results to the use of vision as a substitute communication channel for language were discussed.
