Search PubMed⌕ Search

Biomedical subjects

D W Sparks

Publications and source records attributed to D W Sparks.

7 recordsLinked to original sources
PubMed1986

The transmission of prosodic information via an electrotactile speechreading aid.

Variations in voice fundamental frequency were extracted from naturally produced speech samples and transmitted to an electrocutaneous display consisting of 10 electrodes arranged in a linear array along the forearm. Changes in fundamental frequency were encoded as changes in stimulus location. Speechreading performance, with and without the electrocutaneous aid, was examined for both sentence and connected discourse materials with one profoundly hearing-impaired listener and one normally hearing listener whose hearing was masked. After 20 hours of speechreading training in connected discourse tracking procedure, both subjects showed higher tracking rates and faster learning rates with the aid than without the aid. Results from closed-set sentence-identification tests showed that patterns of intonation, stress, and phrase structure, which are not easily speechread, are readily available with the aid.

Adult↗
PubMed1985

The contribution of fundamental frequency, amplitude envelope, and voicing duration cues to speechreading in normal-hearing subjects.

The ability to combine speechreading (i.e., lipreading) with prosodic information extracted from the low-frequency regions of speech was evaluated with three normally hearing subjects. The subjects were tested in a connected discourse tracking procedure which measures the rate at which spoken text can be repeated back without any errors. Receptive conditions included speechreading alone (SA), speechreading plus amplitude envelope cues (AM), speechreading plus fundamental frequency cues (FM), and speechreading plus intensity-modulated fundamental frequency cues (AM + FM). In a second experiment, one subject was further tested in a speechreading plus voicing duration cue condition (DUR). Speechreading performance was best in the AM + FM condition (83.6 words per minute,) and worst in the SA condition (41.1 words per minute). Tracking levels in the AM, FM, and DUR conditions were 73.7, 73.6, and 65.4 words per minute, respectively. The average tracking rate obtained when subjects were allowed to listen to the talker's normal (unfiltered) speech (NS condition) was 108.3 words per minute. These results demonstrate that speechreaders can use information related to the rhythm, stress, and intonation patterns of speech to improve their speechreading performance.

Adult↗
PubMed1979

Investigating the MESA (multipoint electrotactile speech aid): the transmission of connected discourse.

Three normal-hearing young adults were tested in their reception of connected discourse materials under two receiving conditions; visual-reception alone (lipreading) and visual reception in conjunction with an electrotactile speech aid (MESA). Subjects were artificially deafened with earplugs and white noise; all stimuli were delivered live-voice using a special tracking procedure. Analysis of the data suggests that after an initial period of learning, combined visual and electrotactile receptive performance exceeds lipreading-alone performance. After extensive learning however, performance in lipreading alone or MESA plus lipreading is practically equivalent.

Adult↗
PubMed1978

Investigating the MESA (multipoint electrotactile speech aid): the transmission of segmental features of speech.

Four normal-hearing young adults have been extensively trained in the use of a tactile speech-transmission system. Subjects were tested in the recognition of various phonetic elements including vowels, and stop, nasal, and fricative consonants under three receiving conditions; visual reception alone (lipreading), tactile reception alone, and tactile plus visual reception. Subjects were artificially deafened using earplugs and white noise and all speech tokens were presented live voice. Analysis of the data demonstrates that the tactile transform enables receivers to achieve excellent recognition of vowels in CVC context and the consonantal features of voicing and nasality. This, in combination with high recognition of vowels and the consonantal feature place of articulation through visual receptors, leads to recognition performance in the combined condition (visual plus tactual) which far exceeds either reception condition in isolation.

Abdomen↗