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N I Durlach

Publications and source records attributed to N I Durlach.

67 records · Page 4Linked to original sources

Analytic study of the Tadoma method: discrimination ability of untrained observers.

This study reports the ability of two observers with normal-hearing and sight to discriminate pairs of speech elements through the Tadoma method of speechreading. The observers were blindfolded and exposed to masking noise to eliminate visual and auditory cues. They placed their right hand over the speaker's face and neck so that the thumb rested lightly on the lips and the fingers fanned out over the cheek and neck. The discrimination tests were conducted using an ABX procedure. Average discrimination scores for the five types of test materials used in the ABX tests were 87% on W-22 words, 83% on Modified Rhyme Test words, 70% on vowels, 77% on CV and VC nonsense syllables, and 71% on consonant clusters. In all of the ABX tests, the inexperienced observers performed at least as well as the experienced Tadoma user studied by Norton, et al (1977). This finding indicates that the basic tactile sensitivity of inexperienced observers is comparable to that of an experienced deaf-blind Tadoma user.

Cues↗

Intensity perception. IX. Effect of a fixed standard on resolution in identification.

This note reports some measurements of the changes in identification performance that result form presenting a fixed standard before each trial. These measurements indicate that the presence of the standard improves performance for test stimuli in the vicinity of the standard, except when the standard is near the extremes of the stimulus range.

Discrimination, Psychological↗

Analytic study of the Tadoma method: background and preliminary results.

Certain deaf-blind persons have been taught, through the Tadoma method of speechreading, to use vibrotactile cues from the face and neck to understand speech. This paper reports the results of preliminary tests of the speechreading ability of one adult Tadoma user. The tests were of four major types: (1) discrimination of speech stimuli; (2) recognition of words in isolation and in sentences; (3) interpretation of prosodic and syntactic features in sentences; and (4) comprehension of written (Braille) and oral speech. Words in highly contextual environments were much better perceived than were words in low-context environments. Many of the word errors involved phonemic substitutions which shared articulatory features with the target phonemes, with a higher error rate for vowels than consonants. Relative to performance on word-recognition tests, performance on some of the discrimination tests was worse than expected. Perception of sentences appeared to be mildly sensitive to rate of talking and to speaker differences. Results of the tests on perception of prosodic and syntactic features, while inconclusive, indicate that many of the features tested were not used in interpreting sentences. On an English comprehension test, a higher score was obtained for items administered in Braille than through oral presentation.

Adult↗

Intensity perception. VIII. Loudness comparisons between different types of stimuli.

In this paper, we describe an extension of our preliminary theory of intensity resolution [Durlach and Braida, J. Acoust. Soc. Am. 46, 372-383 (1969)] to include loudness comparisons among different types of stimuli. The extended theory relates mean loudness matches to discrimination and provides a framework for the interpretation of results on the intrasubject variability of loudness comparisons. The predicted relation between mean loudness matches and discrimination is essentially the same as that proposed by Riesz [J. Acoust. Soc. Am. 5, 211-216 (1933)]. With regard to the variability of loudness comparisons, the extended model is essentially the same as the preliminary model except that a new term is included in the trace-mode memory variance to account for the dissimilarity of the stimuli being compared. The model is compared to some published data on loudness matching and discrimination and to some new data of our own on the variability of loudness comparisons obtained in a two-interval, roving-level, loudness-discrimination experiment.

Acoustic Stimulation↗