Citations

This study examined the possibility that hearing-impaired listeners, in addition to displaying poorer-than-normal recognition of speech presented in background noise, require a larger signal-to-noise ratio for the detection of the speech sounds. Psychometric functions for the detection and recognition of stop consonants were obtained from both normal-hearing and hearing-impaired listeners. Expressing the speech levels in terms of their short-term spectra, the detection of consonants for both subject groups occurred at the same signal-to-noise ratio. In contrast, the hearing-impaired listeners displayed poorer recognition performance than the normal-hearing listeners. These results imply that the higher signal-to-noise ratios required for a given level of recognition by some subjects with hearing loss are not due in part to a deficit in detection of the signals in the masking noise, but rather are due exclusively to a deficit in recognition.

This study investigated the effects of visual and inferential complexity on the pictured scene descriptions of right-hemisphere-damaged (RHD) and non-brain-damaged (NBD) adults. The number and accuracy of noun phrases generated by both groups were significantly affected by the inferential complexity of pictured scenes, but not by their visual complexity (as measured by the number of objects and amount of object embedding in the scenes). RHD subjects, particularly those with high levels of neglect, were significantly impaired relative to the NBD subjects in generating accurate inferences from the pictures, but not in their ability to recognize and identify pictured elements.

Distortion product otoacoustic emissions (DPOAEs) measured from the ear canal can be a sensitive tool to detect changes in cochlear function over time. However, if multiplemeasurement procedures are to be useful clinically, testing needs to be reliable and sources of variability within individuals should be known. Herein, the influence of time-of-day (TOD), stimulus frequency, stimulus sound pressure level (SPL), and gender were evaluated on 2f1-f2 DPOAE amplitude in 16 adult volunteers with normal hearing. The effects of oral temperature and resting-pulse rate were also assessed. This study demonstrated a TOD main effect, with a period approximating one cycle-per-day. The magnitude of this effect averaged less than one dB and was not dependent on stimulus (frequency or SPL) or participant variables (gender, oral temperature, or resting-pulse rate), nor was it synchronized to a particular point-in-time. Stimulus level and gender effects on DPOAEs across frequency were also observed. Using generalizability theory (GT), DP iso-level/frequency profiles (DPILFPs) were found to be reliable measures within-subjects over a contiguous 24-hour time period. Significant and reliable between-subject differences were also documented. This study demonstrates the influence of stimulus and participant variables, quantifies the within-subject reliability over a 24-hour time period, and confirms that significant and reliable between-subject differences exist on DPOAEs across frequency, SPL, and gender.

Four groups of 10 patients, each group having a different neurogenic disorder of communication, were tested for impairment in 10 language categories. Five categories—auditory comprehension, adequacy of response, arithmetic, syntax, and naming—although impaired to some degree in all groups, did not sharply differentiate them. The most strongly differentiating disabilities in the four groups were aphasia—auditory retention span and fluency; apraxia of speech—fluency; confused language—relevance, reading comprehension, and writing of words to dictation; and general intellectual impairment—reading comprehension and auditory retention span (with preservation of relevance). The groups differed also in the onset and duration of the communication difficulty, and in the nature and locus of the neurologic problem.

Phoneme duration control in utterances of various lengths was investigated in one apractic subject. Results indicate a loss of segment duration control and a speeding of intrasyllabic articulatory rates in apraxia. Findings are related to a theory of apractic speech dysfunction.

Twenty-seven schizophrenic patients free of any known neurologic deficit were tested with an aphasia test battery. The objective of the research was to derive a profile of schizophrenic language performance to permit its comparison with the profiles characteristic of aphasia, apraxia of speech, generalized intellectual impairment, and confused language. Results indicate that schizophrenic patients exhibit a profile of language performance distinctive from those found in aphasia, apraxia of speech, confusion, or generalized intellectual impairment and demonstrate that the disruption of language in schizophrenia is not aphasic in nature.

This study investigated the practicality of developing short forms of the Porch Index of Communicative Ability (PICA). Stepwise regression procedures were performed using data from 222 complete administrations of the PICA to determine the accuracy of prediction of overall scores on the basis of data from either fewer subtests or fewer items. Results indicated that the PICA is highly redundant and that it may be possible to develop useful shorter forms of it.

Two short versions (SPICAs) of the Porch Index of Communicative Ability (PICA)were developed and investigated, with specific attention to their ability to predict standard PICA overall scores of patients with aphasia. Ninety-three patients were administered three versions of the test in randomized order. Results indicate that SPICAs predict overall scores by standard administration at acceptable confidence levels in approximately one-third of the time required for the administration of the standard PICA.