Scandinavian audiology. Supplementum最新文献

The immediate goal of sensory assistance is to provide as much sensory evidence as possible about the sound patterns of speech. To determine how well this goal has been met calls for tests that are sensitive to sensory capacity and insensitive to linguistic and cognitive status. At the same time, the results should have predictive validity in terms of the potential for developing speech perception skills. This paper describes data obtained from paediatric hearing aid and cochlear implant users by means of an imitative test of phonetic contrast perception (IMSPAC). It is shown that the primary predictor of IMSPAC performance for aided subjects is degree of hearing loss, with little or no influence of age and communication mode. The primary predictors for Nucleus implantees, however, are communication mode and duration of use. The distribution of scores in the implant group is similar to that of hearing aid users with hearing losses in the 90 to 99 dB range. The more successful implantees (mostly, but not only, orally trained) perform like hearing aid users with hearing losses in the 70 to 89 dB range. The hearing aid data suggest that the IMSPAC test is effective in measuring auditory sensory capacity without confounding by linguistic status. If this is true, the implant data must be interpreted as evidence of the development of auditory perceptual skills during the post-implant period. This interpretation carries important implications for issues of cortical plasticity, acclimatization, the management of childhood deafness, and the evaluation of sensory aid efficacy.

Examples from several areas of cochlear implant research are presented, with emphasis on the continuous interleaved sampling (CIS) approach to speech processor design. Within-subject comparisons of such processors with the compressed analog (CA) approach of the clinical Ineraid device are reviewed, and ongoing similar comparisons with the clinical Nucleus spectral peak (SPEAK) strategy are outlined. Correlations between chronic performance levels with clinical CA processors and initial performance levels with CIS, data on further improvements in performance with chronic use of CIS, and instances of substantial benefit from custom fitting of CIS parameters are presented as examples of findings with immediate clinical implications. New studies are described, involving the measurement of intracochlear evoked potentials in response to cochlear implant stimulation, and the integration of such work with computer modeling studies.

Research in the use of vibrotactile devices has focused predominantly on the vibrotactile receptor system within the skin. There is little research relating to the neural pathways and the central processing of information transmitted to the cortex as a result of vibrotactile stimulation. This pilot study that considers the use of vestibulometric measures in predicting the neural pathways. Three measures of vestibular function were undertaken: saccadic eye movement, smooth pursuit and optokinetic nystagmus. Ten normally hearing adults, with no previous history of vestibular dysfunction, were tested using an ICS computer based vestibular testing system. All subjects were tested in four situations: baseline, wearing vibrotactile device with stimulation, vibrotactile device without stimulation and repeated baseline. Five subjects demonstrated a significant change in vestibular measures, four related to measure of optokinetic nystagmus and two in relation to smooth pursuit. There is a demonstrated difference in vestibular function which supports the need for further investigation.

The effects of acoustic/linguistic complexity of training stimuli (i.e., isolated words vs. words in sentences) on speech perception performance was measured in 17 young children (four-to-eight years old) with severe-to-profound sensorineural hearing losses. Phase I of the study involved training on isolated words (n = 9), while Phase II involved training on words in sentences (n = 8). A four-week period of experimental training was counterbalanced with a four-week period of traditional speech-language therapy across participants and Phases. Pre- and post-treatment testing was conducted for both words in isolation and in sentences at the end of each period. Significant improvements were found as a result of experimental training in both phases. Evidence of transfer of learning was greater when sentence level stimuli (Phase II) rather than isolated word stimuli were used (Phase I). Clinical implications are discussed.