Scandinavian audiology. Supplementum最新文献

The OSCAR-project (Optimal Speech Communication Assistance for Residual Abilities) within the TIDE frame is aiming at processing the speech signal in such a way so that it can be more effectively aurally perceived than with an ordinary hearing aid in case of a very small residual hearing. In case of total deafness the code will be tactile and in some cases a multi modal approach will be tried. One of the sub-results of the OSCAR-project is a hand held vibro-tactile speech communication aid for profoundly hard of hearing and deaf persons. The main idea of the aid is that it should not be a general tactile hearing aid, but rather give optimum tactile support to lip-reading in a close communication situation. It should be used when speech communication is necessary and other methods of communication i.e. sign language, lip-reading, reading and writing etc. does not work. The aid conveys two types of information via its two vibro-tactile transducers; the syllabic rhythm and frication. This paper describes some characteristics of the aid and some results.

Motivated by the highly successful Tadoma method of speech communication, a multi-finger positional display (the TACTUATOR) was developed to study perception via the kinesthetic and vibrotactile aspects of the tactual sensory system of the hand. The information transmission capabilities with the TACTUATOR were assessed through a series of absolute identification experiments. An information transfer (IT) of 5.6 to 6.5 bits for stimulus durations of 125 to 500 msec was obtained in absolute-identification experiments with sets of signals derived by varying frequency, amplitude, and site of stimulation of multicomponent waveforms. An estimated IT rate of 12 bits/sec was obtained by sequencing three random stimuli and (a) having the subject identify only the middle stimulus and (b) extrapolating this IT to that for continuous streams. This IT rate is roughly the same as that achieved by Tadoma users in tactual speech communication.

Experiments have been carried out in which subjects were required to discriminate time-varying visual and tactile stimuli presented simultaneously via a 2D array of light-emitting diodes and a vibrator on the fingertip. Contrary to expectations, no problems in parallel visual and tactile perception were apparent. Similar results were obtained in a second experiment in which subjects were require to lipread from a video image and simultaneously identify speech-derived tactile stimuli. The generally poor performance of tactile aids to lipreading has been attributed to problems of parallel perception, but such problems are clearly not present in all circumstances.

We report the speech perception progress and programming procedures of a case of congenital profound deafness and bilateral Mondini dysplasia implanted with a Nucleus 20 + 2 cochlear implant at the age of six. Unclear relations between electrodes array and cochlear partition made implant programming difficult and non-standard procedures were set. Cochlear implantation may give excellent rehabilitative results also in cochleae with malformation.

Nineteen profoundly deaf children who utilize either cochlear implants (CIs) or multichannel tactile aids plus hearing aids (T + HAs) and who were enrolled in a full-day educational program that specializes in the use of sensory aids were evaluated using a battery of speech perception tests either developed in house or chosen because they were part of a standard battery of tests developed for children with sensory aids. The tests were organized into four perceptual levels ranging from pattern perception at level one to open set word identification at level four. For each level, data were analyzed for changes over time and for differences between performance of CI children and those using T + HAs. The results indicate that overall, across levels, both groups improved significantly over time but no differences were found between users of T + HAs and CIs at any level.

We review recent data from the University of Iowa obtained from prelingually deaf children over 3 years using feature-extraction versions of the Nucleus cochlear implant, and from postlingually deaf adults using the compressed-analog Ineraid, a feature-extraction version of Nucleus, and a continuous interleaved sampling version of the Clarion cochlear implant. Both adults and children were followed over a 3-year period. Average results are shown where each patient is represented at each point in time. Results for the children show continued improvement over the 3-year period, with some children obtaining maximum scores possible on the easier closed-set tests. Substantial improvements in audiovisual enhancement were provided by the cochlear implant. Results from the adults show maximum gains within the first year of implant use, although some patients show continued improvements after 2 years of implant use. Adults who have been deaf for several years and who receive their implant when they are older tend not to perform as well as adults who have been deaf for only a few years or receive their implant when they are younger.