Linked Life Data

3156905

Source:http://linkedlifedata.com/resource/pubmed/id/3156905

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1985-5-1
pubmed:abstractText
Tactual vocoders (artificial hearing systems) transduce the acoustic energy of speech into patterns of stimulation that are presented to the skin. In an electrocutaneous tactual vocoder, energy within an acoustic-frequency band is generally represented at a particular skin locus by the rate or frequency of brief electrical pulse bursts. At present little is known about tactual sensitivity for changes in the frequency of brief, bipolar electrical pulses used in several current electrocutaneous vocoder designs. Accordingly, discrimination of frequency change of electrocutaneous bipolar signals was evaluated for standard frequencies of 48, 100, 148, 200, and 248 Hz at signal durations of 50, 100, and 250 ms. Bipolar pulses (height = 10 mA, width = 13 microseconds) were presented on a single electrode placed slightly above and 8 cm to either the left or right of the navel. In a same-different task, three practiced subjects judged pairs of stimuli separated by an interstimulus interval (ISI) of 300 ms. For standard frequencies of 48 and 100 Hz, psychometric functions were similar for all subjects and all signal durations. For these frequencies, delta f/f was constant at approximately 0.3. By contrast, for standard stimuli greater than 100 Hz, the Weber fraction was found to increase dramatically as a function of both standard frequency and signal duration. In a second, similar experiment the Weber fraction for a 248-Hz standard increased as ISI was decreased below 300 ms. By contrast, ISI had little effect on sensitivity for standard stimuli of 48 and 100 Hz. Overall, these results suggest guidelines for possible intensity coding schemes for future electrocutaneous vocoder designs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0001-4966
pubmed:author
pubmed:issnType
Print
pubmed:volume
77
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1192-8
pubmed:dateRevised
2006-12-27
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
The effect of frequency change on discrimination of pulse bursts in an electrocutaneous tactual vocoder.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't