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Biomedical subjects

C R Lansing

Publications and source records attributed to C R Lansing.

5 recordsLinked to original sources
PubMed1992

Natural vowel perception by patients with the ineraid cochlear implant.

Vowel recognition was tested in 10 patients using the Ineraid cochlear implant. The vowels were produced by a male speaker in the context 'heed, hid, head, had, hawed, hood, who'd, hud' and 'heard'. Performance varied from 34 to 93% correct. A descriptive feature system for the vowels was determined from an acoustic analysis. An information transfer analysis of these features suggested that information about the first formant frequency, vowel duration and fundamental frequency was transmitted. Information about the second and third formant frequency was transmitted less well. A sequential information transmission analysis suggested that the features of the first formant and duration accounted for nearly 80% of the information transmitted. The fundamental frequency and second formant frequency information accounted for an additional 8%. Information provided by the third formant frequency was largely redundant.

Adult↗
PubMed1991

Melodic, rhythmic, and timbral perception of adult cochlear implant users.

The purpose of this pilot study was to investigate adult Ineraid and Nucleus cochlear implant (CI) users' perceptual accuracy for melodic and rhythmic patterns, and quality ratings for different musical instruments. Subjects were 18 postlingually deafened adults with CI experience. Evaluative measures included the Primary Measures of Music Audiation (PMMA) and a Musical Instrument Quality Rating. Performance scores on the PMMA were correlated with speech perception measures, music background, and subject characteristics. Results demonstrated a broad range of perceptual accuracy and quality ratings across subjects. On these measures, performance for temporal contrasts was better than for melodic contrasts independent of CI device. Trends in the patterns of correlations between speech and music perception suggest that particular structural elements of music are differentially accessible to cochlear implant users. Additionally, notable qualitative differences for ratings of musical instruments were observed between Nucleus and Ineraid users.

Adult↗
PubMed1990

The relationship between communication problems and psychological difficulties in persons with profound acquired hearing loss.

Communication strategies, accommodations to deafness, and perceptions of the communication environment by profoundly deaf subjects were correlated with indices of psychosocial adjustment to determine whether accommodations to deafness could play a role in the presence of psychological difficulties among deaf persons. Persons with postlingually acquired profound deafness were administered the Communication Profile for the Hearing Impaired (CPHI) and several standardized tests of psychological functioning and adjustment. Inadequate communication strategies and poor accommodations to deafness reported on the CPHI were associated with depression, social introversion, loneliness, and social anxiety. Limited communication performance at home and with friends was related to both social introversion and the experience of loneliness; perceived attitudes and behaviors of others correlated with depression as well as loneliness. In general, the pattern of correlations obtained suggests that specific communication strategies and accommodations to deafness, rather than deafness per se, may contribute to the presence of some psychological difficulties in individuals.

Adult↗
PubMed1986

Previous experience as a confounding factor in comparing cochlear-implant processing schemes.

It is of great importance to compare the relative merits of different cochlear-implant speech-processing strategies. Some groups have compared different strategies within single subjects, but usually the subject has prior experience with one strategy, and no allowance is made for this prior experience. We show in the present study that this is inappropriate. We tested one subject using the Melbourne (Cochlear Corp.) multichannel implant with the device set to process sounds in two different ways. In the first processing scheme, the device functioned normally, extracting information about voicing frequency, amplitude and second-formant frequency. This information activated the 21-channel device, determining pulse rate, pulse amplitude and electrode position (respectively). In the second processing scheme, a single electrode (with the largest dynamic range) was activated. This electrode coded overall amplitude and voicing frequency. The subject was tested on an audiovisual test of a 14-choice consonant recognition in the form /iCi/ over a period of over 4 months. During this time the subject used the 21-channel processor outside of the laboratory. Upon initial connection, there was little difference between the results obtained with the two schemes when tested in sound alone or in sound plus vision. However, after about 4 months, scores obtained with the 21-channel processor in sound plus vision were superior to the scores obtained with the one channel. This advantage came from a superiority in the features of voicing and nasality, but not place. Scores for sound-alone conditions between the two processing schemes remained similar for the 4-month period.(ABSTRACT TRUNCATED AT 250 WORDS)

Auditory Threshold↗