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Hearing Research Apr 2024Auditory detection of the Amplitude Modulation (AM) of sounds, crucial for speech perception, improves until 10 years of age. This protracted development may not only be...
Auditory detection of the Amplitude Modulation (AM) of sounds, crucial for speech perception, improves until 10 years of age. This protracted development may not only be explained by sensory maturation, but also by improvements in processing efficiency: the ability to make efficient use of available sensory information. This hypothesis was tested behaviorally on 86 6-to-9-year-olds and 15 adults using AM-detection tasks assessing absolute sensitivity, masking, and response consistency in the AM domain. Absolute sensitivity was estimated by the detection thresholds of a sinusoidal AM applied to a pure-tone carrier; AM masking was estimated as the elevation of AM-detection thresholds produced when replacing the pure-tone carrier by a narrowband noise; response consistency was estimated using a double-pass paradigm where the same set of stimuli was presented twice. Results showed that AM sensitivity improved from childhood to adulthood, but did not change between 6 and 9 years. AM masking did not change with age, suggesting that the selectivity of perceptual AM filters was adult-like by 6 years. However, response consistency increased developmentally, supporting the hypothesis of reduced processing efficiency in early childhood. At the group level, double-pass data of children and adults were well simulated by a model of the human auditory system assuming a higher level of internal noise for children. At the individual level, for both children and adults, double-pass data were better simulated when assuming a sub-optimal decision strategy in addition to differences in internal noise. In conclusion, processing efficiency for AM detection is reduced in childhood. Moreover, worse AM detection was linked to both systematic and stochastic inefficiencies, in both children and adults.
Topics: Adult; Child; Humans; Child, Preschool; Adolescent; Young Adult; Auditory Threshold; Perceptual Masking; Noise; Speech Perception; Sound
PubMed: 38484447
DOI: 10.1016/j.heares.2024.108982 -
Journal of the Association For Research... Apr 2024Attempts to use current-focussing strategies with cochlear implants (CI) to reduce neural spread-of-excitation have met with only mixed success in human studies, in...
PURPOSE
Attempts to use current-focussing strategies with cochlear implants (CI) to reduce neural spread-of-excitation have met with only mixed success in human studies, in contrast to promising results in animal studies. Although this discrepancy could stem from between-species anatomical and aetiological differences, the masking experiments used in human studies may be insufficiently sensitive to differences in excitation-pattern width.
METHODS
We used an interleaved-masking method to measure psychophysical excitation patterns in seven participants with four masker stimulation configurations: monopolar (MP), partial tripolar (pTP), a wider partial tripolar (pTP + 2), and, importantly, a condition (RP + 2) designed to produce a broader excitation pattern than MP. The probe was always in partial-tripolar configuration.
RESULTS
We found a significant effect of stimulation configuration on both the amount of on-site masking (mask and probe on same electrode; an indirect indicator of sharpness) and the difference between off-site and on-site masking. Differences were driven solely by RP + 2 producing a broader excitation pattern than the other configurations, whereas monopolar and the two current-focussing configurations did not statistically differ from each other.
CONCLUSION
A method that is sensitive enough to reveal a modest broadening in RP + 2 showed no evidence for sharpening with focussed stimulation. We also showed that although voltage recordings from the implant accurately predicted a broadening of the psychophysical excitation patterns with RP + 2, they wrongly predicted a strong sharpening with pTP + 2. We additionally argue, based on our recent research, that the interleaved-masking method can usefully be applied to non-human species and objective measures of CI excitation patterns.
Topics: Animals; Humans; Cochlear Implants; Perceptual Masking; Cochlear Implantation; Electric Stimulation
PubMed: 38459245
DOI: 10.1007/s10162-024-00937-2 -
The Journal of the Acoustical Society... Mar 2024Speech quality is one of the main foci of speech-related research, where it is frequently studied with speech intelligibility, another essential measurement. Band-level...
Speech quality is one of the main foci of speech-related research, where it is frequently studied with speech intelligibility, another essential measurement. Band-level perceptual speech intelligibility, however, has been studied frequently, whereas speech quality has not been thoroughly analyzed. In this paper, a Multiple Stimuli With Hidden Reference and Anchor (MUSHRA) inspired approach was proposed to study the individual robustness of frequency bands to noise with perceptual speech quality as the measure. Speech signals were filtered into thirty-two frequency bands with compromising real-world noise employed at different signal-to-noise ratios. Robustness to noise indices of individual frequency bands was calculated based on the human-rated perceptual quality scores assigned to the reconstructed noisy speech signals. Trends in the results suggest the mid-frequency region appeared less robust to noise in terms of perceptual speech quality. These findings suggest future research aiming at improving speech quality should pay more attention to the mid-frequency region of the speech signals accordingly.
Topics: Humans; Speech Perception; Perceptual Masking; Noise; Speech Intelligibility; Speech Acoustics
PubMed: 38456734
DOI: 10.1121/10.0025272 -
Perception May 2024During the global COVID-19 pandemic, the wearing of face masks became a common practice, raising questions about how masks affect perceptions of and behaviour towards...
During the global COVID-19 pandemic, the wearing of face masks became a common practice, raising questions about how masks affect perceptions of and behaviour towards others. Numerous studies have explored the impact of face masks on perceptions of trustworthiness, but results have been mixed and it remains unclear whether masks influence perceptions via their social meaning or their effects on facial appearance. In this study, Australian participants (= 363) rated a series of faces which were either masked, unmasked, or occluded by a non-mask object (computer) in terms of perceived trustworthiness in 2020, 2022, or 2023. The apparent trustworthiness of unmasked faces remained stable across years, but masked faces were rated significantly more trustworthy in 2020 compared to 2022 and 2023. Furthermore, ratings of masked faces, but not unmasked faces, were correlated with participants' attitudes towards wearing masks. Faces occluded by a non-mask object were perceived to be less trustworthy than masked faces. Together, results strongly suggest the increase in perceived trustworthiness of masked faces reported in numerous studies conducted during COVID-19 were driven by positive social meanings around mask wearing rather than by their effect on facial appearance.
Topics: Humans; Masks; Trust; Female; Male; COVID-19; Adult; Young Adult; Middle Aged; Facial Recognition; Australia; Adolescent; Social Perception; Aged; SARS-CoV-2; Perceptual Masking
PubMed: 38454736
DOI: 10.1177/03010066241237430 -
Frontiers in Aging Neuroscience 2024Perceptual learning (PL) has shown promise in enhancing residual visual functions in patients with age-related macular degeneration (MD), however it requires prolonged...
Perceptual learning (PL) has shown promise in enhancing residual visual functions in patients with age-related macular degeneration (MD), however it requires prolonged training and evidence of generalization to untrained visual functions is limited. Recent studies suggest that combining transcranial random noise stimulation (tRNS) with perceptual learning produces faster and larger visual improvements in participants with normal vision. Thus, this approach might hold the key to improve PL effects in MD. To test this, we trained two groups of MD participants on a contrast detection task with ( = 5) or without ( = 7) concomitant occipital tRNS. The training consisted of a lateral masking paradigm in which the participant had to detect a central low contrast Gabor target. Transfer tasks, including contrast sensitivity, near and far visual acuity, and visual crowding, were measured at pre-, mid and post-tests. Combining tRNS and perceptual learning led to greater improvements in the trained task, evidenced by a larger increment in contrast sensitivity and reduced inhibition at the shortest target to flankers' distance. The overall amount of transfer was similar between the two groups. These results suggest that coupling tRNS and perceptual learning has promising potential applications as a clinical rehabilitation strategy to improve vision in MD patients.
PubMed: 38450381
DOI: 10.3389/fnagi.2024.1326435 -
IEEE Transactions on Visualization and... May 2024We provide the first perceptual quantification of user's sensitivity to radial optic flow artifacts and demonstrate a promising approach for masking this optic flow...
We provide the first perceptual quantification of user's sensitivity to radial optic flow artifacts and demonstrate a promising approach for masking this optic flow artifact via blink suppression. Near-eye HMOs allow users to feel immersed in virtual environments by providing visual cues, like motion parallax and stereoscopy, that mimic how we view the physical world. However, these systems exhibit a variety of perceptual artifacts that can limit their usability and the user's sense of presence in VR. One well-known artifact is the vergence-accommodation conflict (VAC). Varifocal displays can mitigate VAC, but bring with them other artifacts such as a change in virtual image size (radial optic flow) when the focal plane changes. We conducted a set of psychophysical studies to measure users' ability to perceive this radial flow artifact before, during, and after self-initiated blinks. Our results showed that visual sensitivity was reduced by a factor of 10 at the start and for ~70 ms after a blink was detected. Pre- and post-blink sensitivity was, on average, ~O.15% image size change during normal viewing and increased to ~1.5- 2.0% during blinks. Our results imply that a rapid (under 70 ms) radial optic flow distortion can go unnoticed during a blink. Furthermore, our results provide empirical data that can be used to inform engineering requirements for both hardware design and software-based graphical correction algorithms for future varifocal near-eye displays. Our project website is available at https://gamma.umd.edu/ROF/.
Topics: Optic Flow; Computer Graphics; Accommodation, Ocular; Algorithms; Software
PubMed: 38437086
DOI: 10.1109/TVCG.2024.3372075 -
Translational Vision Science &... Mar 2024
PubMed: 38436966
DOI: 10.1167/tvst.13.3.3 -
Cognition May 2024A key issue in recent visual word recognition literature is whether text rotation disrupts the early stages of orthographic processing. Previous research found no masked...
A key issue in recent visual word recognition literature is whether text rotation disrupts the early stages of orthographic processing. Previous research found no masked repetition priming effect when primes were rotated ≥90° in alphabetic languages. The present study investigated the impact of text rotation using logographic (two-character Japanese kanji) words. In Experiment 1, we conducted a masked repetition priming lexical decision experiment with upright and 180° rotated primes. The rotated primes produced a significant priming effect, although the effect was smaller than the upright primes. In Experiment 2, we further examined the effectiveness of 180° rotated primes in two different conditions: the whole words were rotated vs. each constituent character was rotated at their own positions. Both prime types produced significant priming effects of similar magnitudes. These findings suggest that orthographic processing is more robust against text rotation in logographic languages than in alphabetic languages.
Topics: Humans; Rotation; Japan; Reading; Pattern Recognition, Visual; Language; Repetition Priming; Perceptual Masking
PubMed: 38430752
DOI: 10.1016/j.cognition.2024.105759 -
Journal of Dairy Science Feb 2024The objective of this study was to examine the sensory interactions between lactones and ketones in a cheddar simulation matrix through perceptual interaction analysis....
Investigation of the Interaction Between Lactones and Ketones in a Cheddar Cheese Matrix Using Feller's Additive Model, σ-τ Plots, U-Models, and Aroma Addition Experiments.
The objective of this study was to examine the sensory interactions between lactones and ketones in a cheddar simulation matrix through perceptual interaction analysis. The olfactory thresholds of 6 key lactones had values ranging from 8.32 to 58.88 μg/kg, whereas those of the 4 key ketones ranged from 6.61 to 660.69 μg/kg. Both Feller's additive model and σ-τ plots demonstrated complex interactions in 24 binary mixtures composed of the 6 lactones and 4 ketones, including synergy, addition, and masking effects. Specifically, we found that 6 binary mixtures exhibited aroma synergistic effects using both methods. Moreover, the σ-τ plot showed a synergistic effect of aroma in 3 ternary mixtures. The U-model further confirmed the synergistic effects of the 6 groups of binary systems and 3 groups of ternary systems on aroma at actual cheese concentrations. In an aroma addition experiment, the combination of δ-octalactone and diacetyl in binary mixtures had the most pronounced impact on enhancing milk flavor. In ternary mixtures, 2 combinations, namely δ-octalactone/δ-dodecalactone/diacetyl and γ-dodecalactone/δ-dodecalactone/acetoin, significantly enhanced the milky and sweet aroma properties of cheese, while also enhancing the overall acceptability of the cheese aroma.
PubMed: 38428493
DOI: 10.3168/jds.2023-24339 -
BioRxiv : the Preprint Server For... Feb 2024Recognizing speech in noise, such as in a busy street or restaurant, is an essential listening task where the task difficulty varies across acoustic environments and...
Recognizing speech in noise, such as in a busy street or restaurant, is an essential listening task where the task difficulty varies across acoustic environments and noise levels. Yet, current cognitive models are unable to account for changing real-world hearing sensitivity. Here, using natural and perturbed background sounds we demonstrate that spectrum and modulations statistics of environmental backgrounds drastically impact human word recognition accuracy and they do so independently of the noise level. These sound statistics can facilitate or hinder recognition - at the same noise level accuracy can range from 0% to 100%, depending on the background. To explain this perceptual variability, we optimized a biologically grounded hierarchical model, consisting of frequency-tuned cochlear filters and subsequent mid-level modulation-tuned filters that account for central auditory tuning. Low-dimensional summary statistics from the mid-level model accurately predict single trial perceptual judgments, accounting for more than 90% of the perceptual variance across backgrounds and noise levels, and substantially outperforming a cochlear model. Furthermore, perceptual transfer functions in the mid-level auditory space identify multi-dimensional natural sound features that impact recognition. Thus speech recognition in natural backgrounds involves interference of multiple summary statistics that are well described by an interpretable, low-dimensional auditory model. Since this framework relates salient natural sound cues to single trial perceptual judgements, it may improve outcomes for auditory prosthetics and clinical measurements of real-world hearing sensitivity.
PubMed: 38405870
DOI: 10.1101/2024.02.13.579526