Modulation detection interference using random and sinusoidal amplitude modulation

To determine the effects of hearing loss and fast-acting compression on auditory grouping based on across-frequency modulation, modulation detection interference (MDI) was measured in listeners with normal hearing and hearing loss. MDI, the increase in the amplitude-modulation detection threshold of a target presented with an interferer distant in frequency, was measured using a 500-Hz target and a 2140-Hz interferer, both modulated with narrow-band noises of the same bandwidth. The two modulated tones were presented at equal loudness levels to listeners with normal hearing and hearing loss in the absence (Exp. 1) and in the presence (Exp. 2) of fast-acting compression applied to the interferer. Modulation detection thresholds increased with increasing modulation depth of the interferer by similar amounts for the two groups of listeners, suggesting that across-frequency grouping based on amplitude modulation is not altered by hearing impairment. Compression provided an additional increase in thresholds for both groups, indicating that compression algorithms might alter across-frequency grouping cues. Partial support for an idea that compression's effect of sharpening the onsets after each envelope valley is provided by a third experiment which found somewhat greater interference produced by square-wave modulation than sine-wave modulation at larger interferer modulation depths.

Section: B Resultscontrasting

confidence: 34%

“…First, Mendoza et al ͑1995͒ found that larger MDIs could be measured using narrow-band noise modulators over sinusoidal modulators. As such, using narrow-band noise modulators might produce larger effects of compression and hearing loss on MDI, making these effects more easily detectable.…”

Section: Introductionmentioning

confidence: 99%

Effect of fast-acting compression on modulation detection interference for normal hearing and hearing impaired listeners

Shen

Lentz

2010

“…The study by Kwon and Turner ͑2001͒ used sinusoidal modulators. A MDI study by Mendoza et al ͑1995͒ indicated that random-noise modulators produce more interference than sinusoidal modulators. It is unclear whether a similar effect of modulator type would be observed with speech signals.…”

Section: A Stimulimentioning

confidence: 97%

Selectivity of modulation interference for consonant identification in normal-hearing listeners

Apoux

Bacon

2008

The present study sought to establish whether speech recognition can be disrupted by the presence of amplitude modulation (AM) at a remote spectral region, and whether that disruption depends upon the rate of AM. The goal was to determine whether this paradigm could be used to examine which modulation frequencies in the speech envelope are most important for speech recognition. Consonant identification for a band of speech located in either the low- or high-frequency region was measured in the presence of a band of noise located in the opposite frequency region. The noise was either unmodulated or amplitude modulated by a sinusoid, a band of noise with a fixed absolute bandwidth, or a band of noise with a fixed relative bandwidth. The frequency of the modulator was 4, 16, 32, or 64 Hz. Small amounts of modulation interference were observed for all modulator types, irrespective of the location of the speech band. More important, the interference depended on modulation frequency, clearly supporting the existence of selectivity of modulation interference with speech stimuli. Overall, the results suggest a primary role of envelope fluctuations around 4 and 16 Hz without excluding the possibility of a contribution by faster rates.

“…In other words, the modulation frequencies introduced by the signal are masked by the modulation frequency spectrum of the noise. Much evidence has been presented recently for the role of masking in the modulation domain, both within channel ͑Bacon and Grantham, 1989;Houtgast, 1989;Dau et al, 1997a,b;across channels ͑Yost andSheft, 1989;Mendoza et al, 1995͒. The effect of the background noise was studied further in experiment 2 by measuring thresholds in noise with various spectral characteristics.…”

Section: E Discussionmentioning

confidence: 99%

Increment and decrement detection in sinusoids as a measure of temporal resolution

Oxenham¹

1997

Link to publication Citation for published version (APA):Oxenham, A. J. (1997). Increment and decrement detection in sinusoids as a measure of temporal resolution. Journal of the Acoustical Society of America, 102(3), 1779-1790. DOI: 10.1121/1.420086 General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Measuring thresholds for the detection of brief decrements in the level of a sinusoid is an established method of estimating auditory temporal resolution. Generally, a background noise is added to the stimulus to avoid the detection of the ''spectral splatter'' introduced by the decrement. Results are often described in terms of a temporal-window model, comprising a band-pass filter, a compressive nonlinearity, a sliding temporal integrator, and a decision device. In this study, thresholds for increments, as well as decrements, in the level of a 55 dB SPL, 4-kHz sinusoidal pedestal were measured as function of increment and decrement duration in the presence of a broadband background noise ranging in spectrum level from Ϫ20 to ϩ20 dB SPL. Thresholds were also measured using a 55-dB, 8-kHz pedestal in the absence of background noise. Thresholds for decrements, in terms of the dB change in level (⌬L), were found to be more dependent on duration than those for increments. Also, performance was found to be dependent on background-noise level over most levels tested. Neither finding is consistent with the predictions of the temporal-window model or other similar models of temporal resolution. The difference between increment and decrement detection was more successfully simulated by using a decision criterion based on the maximum slope of the temporal-window output.