Author
Neal F. Viemeister
Bio: Neal F. Viemeister is an academic researcher from University of Minnesota. The author has contributed to research in topics: Amplitude modulation & Frequency modulation. The author has an hindex of 27, co-authored 100 publications receiving 3376 citations.
Papers published on a yearly basis
Papers
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TL;DR: Although the TMTFs are not directly consistent with the attenuation characteristic of a simple lowpass filter, a model which incorporates such a filter, with a time constant of 2.5 ms, describes the entire TMTF and also describes the modulation functions obtained with square-wave and pulse modulation.
Abstract: The detectability of amplitude modulation in the absence of spectral cues provides a quantitative description of temporal resolution for steady‐state signals with relatively small amplitude changes. Modulation thresholds for sinusoidally amplitude‐modulated wideband noise were measured as a function of modulation frequency. The resulting ’’Temporal Modulation Transfer Function’’ (TMTF) shows a lowpass characteristic for modulation frequencies below about 800 Hz. The lowpass characteristic is extended up to approximately 2 kHz when the increment in average power produced by modulation is eliminated. The important parametric effects are summarized as follows: (1) TMTFs are independent of overall level, except at very low intensities; (2) the time constant indicated by the TMTF decreases as the center frequency of the band‐limited, modulated noise is increased; (3) modulation thresholds generally decrease with increasing duration of modulation, particularly at low modulation frequencies; (4) when the carrier is gated for the duration of modulation, the TMTF shows a highpass segment at low modulation frequencies. Although the TMTFs are not directly consistent with the attenuation characteristic of a simple lowpass filter, a model which incorporates such a filter, with a time constant of 2.5 ms, describes the entire TMTF and also describes the modulation functions obtained with square‐wave and pulse modulation. The wide bandwidth of initial filtering indicated by the model raises the important question of the role of peripheral filtering in determining the detectability of high‐frequency modulation.
719 citations
TL;DR: The data indicate that power integration occurs only for separations less than approximately 5 ms and that the input is sampled at a fairly high rate and that these samples or "looks" are stored in memory and can be accessed and processed selectively.
Abstract: The decrease in detection and discrimination thresholds with increases in signal duration has often been taken to indicate that a process of relatively long‐term temporal integration occurs in hearing. Two experiments are reported that suggest that no such process occurs. The first experiment is similar to the two‐pulse experiment reported by Zwislocki [J. Zwislocki, J. Acoust. Soc. Am. 32, 1046–1059 (1960)] in which the threshold in quiet for a pair of brief pulses is measured as a function of the temporal separation between them. Our data indicate that power integration occurs only for separations less than approximately 5 ms. For separations larger than 5–10 ms, thresholds do not change with separation and the pulses appear to be processed independently. In the second experiment, brief 1‐kHz tone pulses separated by 100 ms are presented during gaps in a wideband noise. The threshold for a pair of pulses is lower than that for either pulse presented alone, indicating that some type of ‘‘integration’’ oc...
362 citations
TL;DR: Modulation thresholds for sinusoidally amplitude-modulated broadband noise were obtained from normal-hearing and sensorineural hearing-impaired listeners as a function of modulation frequency and a similar power-law relationship between modulation threshold and increment threshold was found to exist for both the normal- hearing and the hearing-impaired listeners.
Abstract: Modulation thresholds for sinusoidally amplitude-modulated broadband noise were obtained from normal-hearing and sensorineural hearing-impaired listeners as a function of modulation frequency. The resulting temporal modulation transfer functions (TMTFs) indicated that the impaired listeners were generally less sensitive than the normals to amplitude modulation and, unlike previously published data from normal-hearing listeners, TMTFs in the impaired listeners were level dependent: sensitivity to modulation, particularly for modulation frequencies greater than 100 Hz, decreased with decreases in level. TMTFs were also obtained with band-limited noise from the normal-hearing listeners: the noise was low-pass filtered at 1.6 kHz after modulation and was generally presented with a 1.6-kHz high-pass masker. The TMTFs in the low-pass condition were similar to the TMTFs obtained with broadband noise from the impaired listeners, suggesting that the impaired temporal processing in the hearing-impaired listeners is...
252 citations
TL;DR: Subjects showed excellent within-category discrimination in all three tasks after a moderate amount of training in a same-different task with a fixed standard and with feedback, and discrimination performance continuously improved with increasing stimulus difference for both intra- and intercategory comparisons.
Abstract: The discriminability of bilabial stop consonants differing in VOT (the Abramson–Lisker bilabial series) was measured in a same–different task, an oddity task, and a dual response, discrimination–identification task. Subjects showed excellent within‐category discrimination in all three tasks after a moderate amount of training in a same–different task with a fixed standard and with feedback. In addition, discrimination performance continuously improved with increasing stimulus difference for both intra‐ and intercategory comparisons. Also, subjects were able to alter their identification responses so that well‐defined category boundaries fell at arbitrary values determined by the experimenters. These results are not compatible with a strict interpretation of the categorical perception of stop consonants.
200 citations
TL;DR: Burns and Viemeister as discussed by the authors showed that the pitch-like sensation elicited by sinusoidally amplitude-modulated (SAM) noise can be mediated by short-term spectral information rather than temporal information.
Abstract: The pitchlike sensation elicited by sinusoidally amplitude‐modulated (SAM) noise remains a controversial phenomenon. The controversy centers on two major points: (1) whether this sensation is ’’really’’ pitch rather than, e.g., roughness or intermittency, and (2) the possibility that any pitch sensation is mediated by short‐term spectral information rather than temporal information—thus nullifying an interesting aspect of the phenomenon. Three experiments employing SAM wideband noise, SAM wideband noise bandpass‐filtered after modulation, and a SAM 10 kHz pure tone were performed: (1) open‐set melody identification, (2) melodic dictation, and (3) musical‐interval adjustment. These experiments extend our earlier study [Burns and Viemeister, J. Acoust. Soc. Am. 60, 863 (1976)]. The results provide further evidence that SAM noise can, at suitable modulation frequencies, elicit a sensation of pitch (as defined by the ability to carry melodic information), and that this pitch represents a purely temporal phenomenon.
143 citations
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TL;DR: A motor theory of speech perception, initially proposed to account for results of early experiments with synthetic speech, is now extensively revised to accommodate recent findings, and to relate the assumptions of the theory to those that might be made about other perceptual modes.
2,523 citations
TL;DR: The 'asymmetric sampling in time' hypothesis developed here provides a framework for understanding a range of psychophysical and neuropsychological data on speech perception in the context of a revised cortical functional anatomic model.
1,110 citations
TL;DR: A new framework for describing the acoustic structure of speech based purely on temporal aspects has been developed, which is said to be comprised of three main temporal features, based on dominant fluctuation rates: envelope, periodicity, and fine-structure.
Abstract: The temporal properties of speech appear to play a more important role in linguistic contrasts than has hitherto been appreciated. Therefore, a new framework for describing the acoustic structure of speech based purely on temporal aspects has been developed. From this point of view, speech can be said to be comprised of three main temporal features, based on dominant fluctuation rates: envelope, periodicity, and fine-structure. Each feature has distinct acoustic manifestations, auditory and perceptual correlates, and roles in linguistic contrasts. The applicability of this three-featured temporal system is discussed in relation to hearing-impaired and normal listeners.
1,090 citations
TL;DR: The picture that emerges is that temporal modulations are a critical stimulus attribute that assists us in the detection, discrimination, identification, parsing, and localization of acoustic sources and that this wide-ranging role is reflected in dedicated physiological properties at different anatomical levels.
Abstract: Joris, P. X., C. E. Schreiner, and A. Rees. Neural Processing of Amplitude-Modulated Sounds. Physiol Rev 84: 541–577, 2004; 10.1152/physrev.00029.2003.—Amplitude modulation (AM) is a temporal featu...
856 citations
TL;DR: The effect of smearing the temporal envelope on the speech-reception threshold (SRT) for sentences in noise and on phoneme identification was investigated for normal-hearing listeners, showing a severe reduction in sentence intelligibility for narrow processing bands at low cutoff frequencies.
Abstract: The effect of smearing the temporal envelope on the speech-reception threshold (SRT) for sentences in noise and on phoneme identification was investigated for normal-hearing listeners. For this purpose, the speech signal was split up into a series of frequency bands (width of 1/4, 1/2, or 1 oct) and the amplitude envelope for each band was low-pass filtered at cutoff frequencies of 0, 1/2, 1, 2, 4, 8, 16, 32, or 64 Hz. Results for 36 subjects show (1) a severe reduction in sentence intelligibility for narrow processing bands at low cutoff frequencies (0-2 Hz); and (2) a marginal contribution of modulation frequencies above 16 Hz to the intelligibility of sentences (provided that lower modulation frequencies are completely present). For cutoff frequencies above 4 Hz, the SRT appears to be independent of the frequency bandwidth upon which envelope filtering takes place. Vowel and consonant identification with nonsense syllables were studied for cutoff frequencies of 0, 2, 4, 8, or 16 Hz in 1/4-oct bands. Results for 24 subjects indicate that consonants are more affected than vowels. Errors in vowel identification mainly consist of reduced recognition of diphthongs and of confusions between long and short vowels. In case of consonant recognition, stops appear to suffer most, with confusion patterns depending on the position in the syllable (initial, medial, or final).
856 citations