Journal ArticleDOI
Speech intelligibility as a function of the number of channels of stimulation for signal processors using sine-wave and noise-band outputs
TLDR
The results of an experiment in which frequency information was altered but temporal information was not altered indicates that vowel recognition is based on information in the frequency domain even when the number of channels of stimulation is small.Abstract:
Vowels, consonants, and sentences were processed through software emulations of cochlear-implant signal processors with 2-9 output channels. The signals were then presented, as either the sum of sine waves at the center of the channels or as the sum of noise bands the width of the channels, to normal-hearing listeners for identification. The results indicate, as previous investigations have suggested, that high levels of speech understanding can be obtained using signal processors with a small number of channels. The number of channels needed for high levels of performance varied with the nature of the test material. For the most difficult material--vowels produced by men, women, and girls--no statistically significant differences in performance were observed when the number of channels was increased beyond 8. For the least difficult material--sentences--no statistically significant differences in performance were observed when the number of channels was increased beyond 5. The nature of the output signal, noise bands or sine waves, made only a small difference in performance. The mechanism mediating the high levels of speech recognition achieved with only few channels of stimulation may be the same one that mediates the recognition of signals produced by speakers with a high fundamental frequency, i.e., the levels of adjacent channels are used to determine the frequency of the input signal. The results of an experiment in which frequency information was altered but temporal information was not altered indicates that vowel recognition is based on information in the frequency domain even when the number of channels of stimulation is small.read more
Citations
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Journal ArticleDOI
Speech recognition in noise as a function of the number of spectral channels: Comparison of acoustic hearing and cochlear implants
TL;DR: The results quantify the effect of number of spectral channels on speech recognition in noise and demonstrate that most CI subjects are not able to fully utilize the spectral information provided by the number of electrodes used in their implant.
Journal ArticleDOI
The neural basis of temporal processing
TL;DR: It is suggested that, given the intricate link between temporal and spatial information in most sensory and motor tasks, timing and spatial processing are intrinsic properties of neural function, and specialized timing mechanisms such as delay lines, oscillators, or a spectrum of different time constants are not required.
Journal ArticleDOI
Factors associated with development of speech perception skills in children implanted by age five.
TL;DR: Children with profound hearing loss achieved unprecedented levels of speech perception skill 4 to 7 yr after cochlear implantation, and use of an updated speech processor contributed significantly to improved speech perception skills, even in children who were initially fitted with an earlier strategy, such as M-PEAK.
Journal ArticleDOI
Modulation spectra of natural sounds and ethological theories of auditory processing.
TL;DR: It is shown how to create synthetic sounds with first and second order envelope statistics identical to those found in natural sounds, and postulated that the auditory system as well as engineering applications may exploit these statistical properties to obtain an efficient representation of behaviorally relevant sounds.
Journal ArticleDOI
Speech recognition with amplitude and frequency modulations
Fan-Gang Zeng,Kaibao Nie,Ginger S. Stickney,Ying-Yee Kong,Michael Vongphoe,Ashish Bhargave,Chao-gang Wei,Ke-li Cao +7 more
TL;DR: It is found that although AM from a limited number of spectral bands may be sufficient for speech recognition in quiet, FM significantly enhancesspeech recognition in noise, as well as speaker and tone recognition.
References
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Journal ArticleDOI
Control Methods Used in a Study of the Vowels
TL;DR: Control methods used in the evaluation of effects of language and dialectal backgrounds and vocal and auditory characteristics of the individuals concerned in a vowel study program at Bell Telephone Laboratories are discussed.
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Speech recognition with primarily temporal cues.
TL;DR: Nearly perfect speech recognition was observed under conditions of greatly reduced spectral information; the presentation of a dynamic temporal pattern in only a few broad spectral regions is sufficient for the recognition of speech.
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Development of the Hearing In Noise Test for the measurement of speech reception thresholds in quiet and in noise
TL;DR: The mean-squared level of each digitally recorded sentence was adjusted to equate intelligibility when presented in spectrally matched noise to normal-hearing listeners, and statistical reliability and efficiency suit it to practical applications in which measures of speech intelligibility are required.
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Acoustic characteristics of American English vowels
TL;DR: Analysis of the formant data shows numerous differences between the present data and those of PB, both in terms of average frequencies of F1 and F2, and the degree of overlap among adjacent vowels.
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Some Experiments on the Perception of Synthetic Speech Sounds
TL;DR: In this article, the acoustic cues to the perception of some of the consonant sounds have been explored using synthetic methods applied to isolated syllables, and the results, results, and working hypotheses are discussed.