Biomedical subjects

E Miskiel

Publications and source records attributed to E Miskiel.

8 recordsLinked to original sources

PubMed1992

FFT-based digital tactile vocoder system for real-time use.

A microprocessor-based real-time digital vibrotactile vocoder system has been developed to train the deaf and for artificial hearing research. The system is composed of a microcomputer module with a digital signal processor, interface units and an attenuator/driver circuit. Live or digitised (stored or synthetic) speech is presented to the skin spectrally through a belt housing eight or 16 vibrators. Speech is processed in real time using a fast Fourier transform. The system is also capable of presenting any arbitrary spatiotemporal pattern on the skin for artificial hearing experiments. A preliminary experiment with a deaf subject indicates that the system is potentially an effective device for artificial hearing.

Biomedical Engineering↗

PubMed1991

Optimization of automated hearing test algorithms: simulations using an infant response model.

Computer simulation was used to evaluate several parameters of an automated hearing test algorithm in an attempt to optimize the algorithm for accuracy and efficiency. An infant response model was developed to guide the simulations. Test parameters of interest were starting intensity and stopping rule and their interaction with a measure that is thought to emulate infant reliability, probability of task orientation. Results indicated that stopping rule, within the ranges investigated, had little effect on accuracy but had major impact on efficiency. Starting intensity interacted with the hearing status of pseudosubjects in influencing accuracy. Accuracy was most influenced by probability of task orientation. The simulated test data are compared to data from infants and young children in the accompanying article so that the response model can be evaluated.

Algorithms↗

PubMed1991

The stop/glide boundary shift: modelling perceptual data.

Research in speech perception has suggested that listeners often adjust category boundary locations for differing contexts. The stop/glide (e.g.,/ba/vs./wa/) boundary shift occurring with changes in syllable duration has been interpreted as reflecting 'rate normalization' by some, whereas others have suggested an auditory basis for the shift. Clarification of both the causes and the effects of the stop/glide shift is being sought through experimentation intended to expand our knowledge of variations in the shift across different experimental treatments. The present study extends research on the stop/glide shift by (1) showing that the shift is not an artifact of a particular stimulus pattern that had been present in all the previous studies of the effect, (2) further demonstrating the nonlinear character of the identification shift, (3) providing additional evidence of the role of presentation format (mixed vs. blocked) in the identification shift, and (4) exploring boundary locations in various discrimination paradigms. The complex outcomes of the studies reported here as well as a variety of previous results are interpreted as compatible with expanded versions of the durational contrast hypothesis. Two versions are considered, one in which the shift is seen as due to a mechanism of contrastive perception that applies to events of comparable duration, and one in which the shift is seen as a perceptual error that occurs when the auditory system attempts to track frequency trajectories that change (i.e., pivot) over time.

Adult↗

PubMed1990

Classification of audiograms by sequential testing using a dynamic Bayesian procedure.

A new method for estimating audiograms using behavioral responses is presented. The method is based upon a modification of the Bayesian probability formula in which an outcome is predicted from a static set of events. In the new method, classification of audiograms by sequential testing (CAST), the probabilities of occurrence of audiogram patterns are dynamically updated according to the outcome of each test trial. Computer simulation using an infant response model suggests that the procedure is efficient, sensitive, and specific.

Algorithms↗

PubMed1989

The effects of vocoder filter configuration on tactual perception of speech.

Perception of synthetic speech continua through the sense of touch and audition was compared utilizing a 32-channel spectrally-oriented electrocutaneous vocoder display and standard auditory psychophysical procedures. Perception of a consonantal and a vocalic continuum was evaluated utilizing three vocoder filter configurations: logarithmic, linear, and average (geometric mean of logarithmic and linear). Results indicated a close correspondence between tactual and auditory discrimination and identification for the vowel (/a/-/e/) and the consonant (/sta/-/sa/) continuum regardless of the filter characteristics.

Deafness↗

PubMed1988

Computer system for quantitative evaluation of an electrotactile vocoder for artificial hearing.

A computer-controlled experimental electrotactile vocoder system is designed to evaluate quantitatively the transmission of speech information and to test various design options for tactual vocoders. The system is composed of a digital speech synthesizer, a digital vocoder, a computer-driven electrotactile display, and an adaptive controller for psychophysical experimentation. Samples of continua representing speech contrast types occurring in natural languages are synthesized by systematically manipulating selected subphonemic features. The synthesized speech stimuli are processed using a programmable vocoder and presented to the skin with an electrotactile display belt worn on the abdomen. Transmission of significant speech parameters is quantitatively evaluated using adaptive psychophysical techniques and labeling tests. The system is used to assess the potential of speech transmission through the skin and to evaluate different vocoder configurations and processing techniques for tactual vocoders to be used as artificial hearing devices by the deaf.

Adult↗

PubMed1988

Similarities between tactual and auditory speech perception.

Perception of synthetic speech continua through the sense of touch and audition was compared utilizing a 32-channel spectrally oriented electrocutaneous display and standard auditory psychophysical procedures. Results indicated a close correspondence between tactual and auditory discrimination and identification for a vowel (/a/-/e/) and a consonant (/sta/-/sa/) continuum. These results suggest that at least some aspects of speech perception are amodal.

Humans↗

PubMed1987

Computer monitoring of auditory brainstem responses.

A relatively low cost, bedside, portable, microcomputer based system for long-term monitoring of human auditory evoked responses in critical care environments is described, and test data are presented. The system enables the user to acquire responses, detect significant peaks (usually peaks I, III, and V), store information and display trends (latency vs time graphs) automatically. Prior to processing, responses are digitally filtered so that no phase distortion is introduced. A peak detection algorithm takes into consideration both the different morphologies of the IV-V wave complex and the time-varying characteristics of the ABR waveform. Evaluations using normal subjects and intensive care unit patients show the clinical potential of automated long-term auditory brainstem monitoring.

Brain Stem↗