Biomedical subjects

M E Demorest

Publications and source records attributed to M E Demorest.

27 records · Page 2Linked to original sources

PubMed1990

Speechreading sentences with single-channel vibrotactile presentation of voice fundamental frequency.

The main goal of this study was to investigate the efficacy of four vibrotactile speechreading supplements. Three supplements provided single-channel encodings of fundamental frequency (F0). Two encodings involved scaling and shifting glottal pulses to pulse rate ranges suited to tactual sensing capabilities; the third transformed F0 to differential amplitude of two fixed-frequency sinewaves. The fourth supplement added to one of the F0 encodings a second vibrator indicating high-frequency speech energy. A second goal was to develop improved methods for experimental control. Therefore, a sentence corpus was recorded on videodisc using two talkers whose speech was captured by video, microphone, and electroglottograph. Other experimental control issues included use of visual-alone control subjects, a multiple-baseline, single-subject design replicated for each of 15 normal-hearing subjects, sentence and syllable pre- and post-tests balanced for difficulty, and a speechreading screening test for subject selection. Across 17 h of treatment and 5 h of visual-alone baseline testing, each subject performed open-set sentence identification. Covariance analyses showed that the single-channel supplements provided a small but significant benefit, whereas the two-channel supplement was not effective. All subjects improved in visual-alone speechreading and maintained individual differences across the experiment. Vibrotactile benefit did not depend on speechreading ability.

Adult↗

PubMed1989

Relationships among behavioral, environmental, and affective communication variables: a canonical analysis of the CPHI.

Relationships among the four content domains assessed by the Communication Profile for the Hearing Imparied (Demorest & Erdman, 1986, 1987) were examined in two samples (N = 433 and N = 486) drawn from the Aural Rehabilitation Program at Walter Reed Army Medical Center. Communication performance was weakly related to communication environment, communication strategies, and personal adjustment (average canonical r = .34). However, strong associations were observed among the latter three areas (average canonical r = .59). Eight specific relationships were identified. The nature of these relationships and implications for clinical intervention are discussed.

Adult↗

PubMed1989

Factor structure of the communication profile for the hearing impaired.

Factor structure of 23 scales of the Communication Profile for the Hearing Impaired (CPHI) (Demorest & Erdman, 1986, 1987) was examined in a sample of 1,226 patients who participated in the Aural Rehabilitation Program at Walter Reed Army Medical Center from 1985 through 1987. Five factors were identified: Adjustment, Reaction, Interaction, Communication Performance, and Communication Importance. To enhance clinical interpretation of the CPHI, it is recommended that factor scores be added to the communication profile.

Communication↗

PubMed1989

Single-channel vibrotactile supplements to visual perception of intonation and stress.

Two experiments were conducted to explore the effectiveness of a single vibrotactile stimulator to convey intonation (question versus statement) and contrastive stress (on one of the first three words of four 4- or 5-word sentences). In experiment I, artificially deafened normal-hearing subjects judged stress and intonation in counterbalanced visual-alone and visual-tactile conditions. Six voice fundamental frequency-to-tactile transformations were tested. Two sentence types were voiced throughout, and two contained unvoiced consonants. Benefits to speechreading were significant, but small. No differences among transformations were observed. In experiment II, only the tactile stimuli were presented. Significant differences emerged among the transformations, with larger differences for intonation than for stress judgments. Surprisingly, tactile-alone intonation identification was more accurate than visual-tactile for several transformations.

Communication Devices for People with Disabilities↗

PubMed1988

Retest stability of the communication profile for the hearing impaired.

Retest stability of the Communication Profile for the Hearing Impaired (CPHI) was assessed in a sample of 101 active-duty military personnel who attended the Aural Rehabilitation Program at Walter Reed Army Medical Center. Pretests were administered by referring audiologists; retests were administered from 6 to 40 weeks later, at the beginning of the rehabilitation program. Mean scores on 5 of the 25 scales of the CPHI decreased significantly (p less than 0.01) over time, but the changes were small in magnitude (approximately -0.20). Distributions of retest-test differences were used to establish criteria for inferring significant improvement in scores over time. Retest correlations for scales in the communication environment, communication strategies, and personal adjustment areas ranged from 0.58 to 0.78. Communication performance and communication importance were less stable (r = 0.28 to 0.54). Retest correlations were comparable for short versus long retest intervals, but varied as a function of military rank. Implications of the results for clinical use of the CPHI are discussed.

Adaptation, Psychological↗

PubMed1987

Development of the communication profile for the hearing impaired.

The rehabilitative needs of hearing-impaired adults depend on the degree of communication handicap experienced and on many other factors (environmental, behavioral, emotional, and attitudinal) that contribute to communication problems. The Communication Profile for the Hearing Impaired (CPHI) is a 145-item self-assessment inventory for adults. Its 25 scales encompass four areas: Communication Performance, Communication Environment, Communication Strategies, and Personal Adjustment. The inventory was developed at Walter Reed Army Medical Center and pilot tested over a 3-year period on 827 patients who attended the Aural Rehabilitation Program at the Army Audiology and Speech Center. The rationale and methods used to develop the CPHI are discussed, and normative data for the Walter Reed population are presented.

Adult↗

PubMed1986

Scale composition and item analysis of the Communication Profile for the Hearing Impaired.

The Communication Profile for the Hearing Impaired (CPHI) is a self-assessment inventory that provides 25 scores describing the Communication Performance, Communication Environment, Communication Strategies, and Personal Adjustment of hearing-impaired adults (Demorest & Erdman, 1986). Description of the content and measurement objective for each scale is given and an analysis of the psychometric properties of the 145 items in the CPHI is presented. Results are based on a sample of 433 active-duty military personnel tested at Walter Reed Army Medical Center during the final phase of CPHI development. Included are frequency distributions, descriptive statistics, item-total correlations, and factor structure of the items within each scale and across scales within each of the areas assessed by the CPHI. Applications of these data in clinical interpretation, construct validation, and further development of the CPHI scales are discussed.

Adult↗

PubMed1984

Psychometric principles in the selection, interpretation, and evaluation of communication self-assessment inventories.

A variety of self-assessment inventories have been introduced in recent years for use with hearing-impaired patients. These instruments differ considerably, both conceptually and operationally. Audiologists, therefore, are faced with the task of selecting a test instrument that is appropriate to their patient population and testing purpose. This paper outlines the psychometric principles that guide the selection, interpretation, and evaluation of self-assessment inventories. The application of these principles to a specific clinical population is illustrated by three studies of the Hearing Performance Inventory (Giolas, Owens, Lamb, & Schubert, 1979) conducted at Walter Reed Army Medical Center (WRAMC).

Adolescent↗

PubMed1984

Self-report approach to assessing benefit derived from amplification.

The ultimate goal of hearing aid selection procedures is successful use of amplification in everyday communication. The need to validate selection procedures is widely recognized, but the development of relevant criterion measures is a prerequisite to evaluation of predictive validity. This study explored the feasibility of using a self-report method of measuring success with amplification. A 64-item questionnaire was administered to 128 experienced hearing aid users who rated the benefit received from amplification in a variety of situations. Internal consistency reliability was excellent (alpha = .96), indicating that the perceived benefit is sufficiently consistent across situations to yield reliable measures of individual differences among patients. Factor analysis of the interitem correlation matrix, however, led to the identification of four types of situations that might be assessed separately: (a) noisy situations; (b) quiet situations with the speaker in proximity; (c) situations with reduced signal information; and (d) situations with nonspeech stimuli. In general, patients reported significantly more benefit from their aids in quiet situations than in noise. A self-report methodology for measuring successful use of amplification in daily life appears promising as a criterion measure in predictive validation studies of hearing aid selection procedures.

Adult↗