Word List Reading Research Articles

Effects of hyperbaric HeO2 breathing mixtures on divers' speech

It has been shown that heliox breathing mixtures, plus high ambient pressures, have a deleterious effect upon speech communication. This report attempts to provide more comprehensive information relative to the effects of the HeO2/P environment on speech—especially speech intelligibility, speaking fundamental frequency, and vowel formant shifts; data also are reported on the performance of a speech processor (i.e., the Marconi “unscrambler”). The data base was developed from the recorded speech of divers who read word lists during the decompression phase of a 1600‐ft dive; the speech at the surface and at 560, 1000, 1400, and 1600 fsw was analyzed. Speech intelligibility was found to be severely degraded as a function of depth and helium concentration—but not as seriously as had been reported earlier. These effects probably were due to the experience of the divers and improved equipment. As expected, speaking fundamental frequency rose as a function of increasing depth; the shifts were consistent with those previously reported. The vowel formant data provide, for the first time, a comprehensive evaluation of the HeO2 effects on these speech features. As expected, the data revealed an upward shift in the formants as a function of increasing depth but the patterns were not as systematic as expected. The data were utilized to compute “K factors” for the formant shifts [G. Fant and J. Lindquist, STL‐QPR 1, 7–17 (1968)]. Finally, the effectiveness of the Marconi system, and its implications, will be discussed. [Work supported by the Norwegian Underwater Institute, Bergen.]

The Effects of Adverse Environmental Conditions on Workload

The present study was conducted to investigate the effects of environmental conditions on visual workload. The environmental variables used were temperature, studied at levels of 45°F., WBGT, and 95°F., WBGT; and noise, studied at 83 dBA intermittent noise and 93 dBA continuous noise. Workload was defined as the amount of attention demanded from an operator as measured by performance decrement on a secondary task while performing a primary and secondary task simultaneously. The secondary task was reading random numbers, and the primary task was reading word lists. Significant differences (p<.05) were found between the control condition and all experimental conditions. The low temperature and high temperature-continuous noise conditions were significantly different from the other conditions. Noise and temperature were found to significantly increase workload (p<05).

Acoustic Analyses of Phonological Processes in Spontaneous and Read Speech

There are many reasons why most phonetic studies have been made based on data from read word lists or sentences. However, in doing so, it is interesting to know some ways in which this speech differs systematically from the informant's natural speech patterns. While for many studies reading passages or word lists will remain the only feasible practice, it is helpful to be able to hypothesize in what ways such data may differ from vernacular speech. It has been found in systematic parallel analyses made of natural speech and reading lists of the same subject, that, as would be expected, certain patterns of phones emerge which may differ from each other from style to style. For example, in recent analyses of sound change in progress, Labor has found that a phonological unit whose position within phonetic space is in flux will, in its progress toward a new target position, order its allophones in space according to the immediate phonetic environment. Often the environmental influence is much larger than mere coarticulation, and in many cases influences the phone in a contrary direction. This patterning of allophones has been documented for several speakers of a dialect in which the phone is changing. Yet before the change, or after it is complete, no such environmental influence is determinable. However, in the reading style of the same speaker with fine phonetic patterning of allophones in his natural style, these patterns will become obscured. [Work supported in part by an NSF Grant.]

Short-term memory processes in the deaf.

Two experiments are reported. In the first, profoundly deaf schoolboys read consonant sequences for immediate written recall, reading, according to instruction, either silently or aloud. Detailed error analysis suggested a dichotomous classification of subjects into those primarily relying on artioulatory coding (A group) and those relying on some other mediating code which could depend on shape (non‐A group). This classification correlated significantly with teachers' ratings of speech quality.The A group showed no effect of reading mode on total number of errors. But the non‐A group were significantly worse when reading aloud. Errors were distributed across serial positions effectively identically, regardless both of coding behaviour and reading mode. A recency effect was found of an order somewhere between that for hearing subjects reading this kind of material silently and reading it aloud.A test of the reliability of the classification into A group and non‐A group was made in the second experiment. In this the same subjects silently read word lists for immediate written recall. Lists were drawn from one of two vocabularies: one consisting of five pairs of common homophones, the other of five pairs of common words assumed to look similar. The A group recalled significantly more words of the latter lists, while the non‐A group recalled both lists equally well.The results are discussed in relation to current models for short‐term memory and to their implications for the education of the deaf. In the former connexion, the presence of recency with subjects who have no auditory feedback would be an embarrassment to ‘echo‐box’‐type accounts of recall. With respect to the latter, two main points are made: (1) Deaf school children do not all memorize in the same code, and for some it may be different from that used by teachers. (2) If memorizing names of things is impaired by reciting them aloud, a hitherto concealed weakness of a common instructional procedure is exposed.