Τετάρτη 17 Οκτωβρίου 2018

Developmental Effects in Children’s Ability to Benefit From F0 Differences Between Target and Masker Speech

Objectives: The objectives of this study were to (1) evaluate the extent to which school-age children benefit from fundamental frequency (F0) differences between target words and competing two-talker speech, and (2) assess whether this benefit changes with age. It was predicted that while children would be more susceptible to speech-in-speech masking compared to adults, they would benefit from differences in F0 between target and masker speech. A second experiment was conducted to evaluate the relationship between frequency discrimination thresholds and the ability to benefit from target/masker differences in F0. Design: Listeners were children (5 to 15 years) and adults (20 to 36 years) with normal hearing. In the first experiment, speech reception thresholds (SRTs) for disyllabic words were measured in a continuous, 60-dB SPL two-talker speech masker. The same male talker produced both the target and masker speech (average F0 = 120 Hz). The level of the target words was adaptively varied to estimate the level associated with 71% correct identification. The procedure was a four-alternative forced-choice with a picture-pointing response. Target words either had the same mean F0 as the masker or it was shifted up by 3, 6, or 9 semitones. To determine the benefit of target/masker F0 separation on word recognition, masking release was computed by subtracting thresholds in each shifted-F0 condition from the threshold in the unshifted-F0 condition. In the second experiment, frequency discrimination thresholds were collected for a subset of listeners to determine whether sensitivity to F0 differences would be predictive of SRTs. The standard was the syllable /ba/ with an F0 of 250 Hz; the target stimuli had a higher F0. Discrimination thresholds were measured using a three-alternative, three-interval forced choice procedure. Results: Younger children (5 to 12 years) had significantly poorer SRTs than older children (13 to 15 years) and adults in the unshifted-F0 condition. The benefit of F0 separations generally increased with increasing child age and magnitude of target/masker F0 separation. For 5- to 7-year-olds, there was a small benefit of F0 separation in the 9-semitone condition only. For 8- to 12-year-olds, there was a benefit from both 6- and 9-semitone separations, but to a lesser degree than what was observed for older children (13 to 15 years) and adults, who showed a substantial benefit in the 6- and 9-semitone conditions. Examination of individual data found that children younger than 7 years of age did not benefit from any of the F0 separations tested. Results for the frequency discrimination task indicated that, while there was a trend for improved thresholds with increasing age, these thresholds were not predictive of the ability to use F0 differences in the speech-in-speech recognition task after controlling for age. Conclusions: The overall pattern of results suggests that children’s ability to benefit from F0 differences in speech-in-speech recognition follows a prolonged developmental trajectory. Younger children are less able to capitalize on differences in F0 between target and masker speech. The extent to which individual children benefitted from target/masker F0 differences was not associated with their frequency discrimination thresholds. ACKNOWLEDGMENTS: This research was supported by grants R01 DC011038 and T32 DC 000012 from the National Institute of Deafness and Other Communications Disorders. Subject recruitment efforts were supported by the Center for Perception and Communication in Children (NIGMS P20 DM109023). The authors declare no conflicts of interest. Received August 10, 2017; accepted August 29, 2018. Address for correspondence Mary M. Flaherty, Department of Speech and Hearing Science, University of Illinois at Urbana-Champaign, 901 South Sixth Street, Champaign, IL 61820, USA. E-mail: maryflah@illinois.edu Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

from #Audiology via ola Kala on Inoreader https://ift.tt/2QYLebP
via IFTTT

Developmental Effects in Children’s Ability to Benefit From F0 Differences Between Target and Masker Speech

Objectives: The objectives of this study were to (1) evaluate the extent to which school-age children benefit from fundamental frequency (F0) differences between target words and competing two-talker speech, and (2) assess whether this benefit changes with age. It was predicted that while children would be more susceptible to speech-in-speech masking compared to adults, they would benefit from differences in F0 between target and masker speech. A second experiment was conducted to evaluate the relationship between frequency discrimination thresholds and the ability to benefit from target/masker differences in F0. Design: Listeners were children (5 to 15 years) and adults (20 to 36 years) with normal hearing. In the first experiment, speech reception thresholds (SRTs) for disyllabic words were measured in a continuous, 60-dB SPL two-talker speech masker. The same male talker produced both the target and masker speech (average F0 = 120 Hz). The level of the target words was adaptively varied to estimate the level associated with 71% correct identification. The procedure was a four-alternative forced-choice with a picture-pointing response. Target words either had the same mean F0 as the masker or it was shifted up by 3, 6, or 9 semitones. To determine the benefit of target/masker F0 separation on word recognition, masking release was computed by subtracting thresholds in each shifted-F0 condition from the threshold in the unshifted-F0 condition. In the second experiment, frequency discrimination thresholds were collected for a subset of listeners to determine whether sensitivity to F0 differences would be predictive of SRTs. The standard was the syllable /ba/ with an F0 of 250 Hz; the target stimuli had a higher F0. Discrimination thresholds were measured using a three-alternative, three-interval forced choice procedure. Results: Younger children (5 to 12 years) had significantly poorer SRTs than older children (13 to 15 years) and adults in the unshifted-F0 condition. The benefit of F0 separations generally increased with increasing child age and magnitude of target/masker F0 separation. For 5- to 7-year-olds, there was a small benefit of F0 separation in the 9-semitone condition only. For 8- to 12-year-olds, there was a benefit from both 6- and 9-semitone separations, but to a lesser degree than what was observed for older children (13 to 15 years) and adults, who showed a substantial benefit in the 6- and 9-semitone conditions. Examination of individual data found that children younger than 7 years of age did not benefit from any of the F0 separations tested. Results for the frequency discrimination task indicated that, while there was a trend for improved thresholds with increasing age, these thresholds were not predictive of the ability to use F0 differences in the speech-in-speech recognition task after controlling for age. Conclusions: The overall pattern of results suggests that children’s ability to benefit from F0 differences in speech-in-speech recognition follows a prolonged developmental trajectory. Younger children are less able to capitalize on differences in F0 between target and masker speech. The extent to which individual children benefitted from target/masker F0 differences was not associated with their frequency discrimination thresholds. ACKNOWLEDGMENTS: This research was supported by grants R01 DC011038 and T32 DC 000012 from the National Institute of Deafness and Other Communications Disorders. Subject recruitment efforts were supported by the Center for Perception and Communication in Children (NIGMS P20 DM109023). The authors declare no conflicts of interest. Received August 10, 2017; accepted August 29, 2018. Address for correspondence Mary M. Flaherty, Department of Speech and Hearing Science, University of Illinois at Urbana-Champaign, 901 South Sixth Street, Champaign, IL 61820, USA. E-mail: maryflah@illinois.edu Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

from #Audiology via ola Kala on Inoreader https://ift.tt/2QYLebP
via IFTTT

Plantarflexor metabolics are sensitive to resting ankle angle and optimal fiber length in computational simulations of gait

Publication date: Available online 17 October 2018

Source: Gait & Posture

Author(s): Josh R. Baxter, Michael W. Hast

Abstract
Background

Plantarflexor structure is an important predictor of function in healthy, athletic, and some patient populations. Computational simulations are powerful tools capable of testing the isolated effects of muscle-tendon structure on gait function.

Research Question

The purpose of this study was to characterize the sensitivity of plantarflexor muscle function based on muscle-tendon unit (MTU) parameters. We hypothesized that plantarflexor metabolics and shortening dynamics would be sensitive to MTU parameters.

Methods

Stance phase of gait was simulated using a musculoskeletal model and computed muscle control algorithm. Optimal muscle fiber length, resting ankle angle, and tendon stiffness parameters were systematically changed to test these effects on plantarflexor metabolics, activation, and power. Dorsiflexor metabolics were also measured to determine the impact of the action of the antagonist muscle group.

Results and Significance

Plantarflexor metabolic demands were 1.5 and 2.7 times more sensitive to optimal fiber length and resting ankle angle, respectively, compared to the effect of tendon stiffness. Increased resting ankle plantarflexion induced a large passive plantarflexion moment during early stance, which required non-physiologic dorsiflexor contractions. Conversely, longer optimal fiber and more neutral resting ankle angles increased the shortening demands of the plantarflexors. These findings highlight the importance of carefully selecting MTU parameters when modeling gait with musculoskeletal models, especially in pathologic or high-performance athlete populations.



from #Audiology via ola Kala on Inoreader https://ift.tt/2Af0fAy
via IFTTT

Plantarflexor metabolics are sensitive to resting ankle angle and optimal fiber length in computational simulations of gait

Publication date: Available online 17 October 2018

Source: Gait & Posture

Author(s): Josh R. Baxter, Michael W. Hast

Abstract
Background

Plantarflexor structure is an important predictor of function in healthy, athletic, and some patient populations. Computational simulations are powerful tools capable of testing the isolated effects of muscle-tendon structure on gait function.

Research Question

The purpose of this study was to characterize the sensitivity of plantarflexor muscle function based on muscle-tendon unit (MTU) parameters. We hypothesized that plantarflexor metabolics and shortening dynamics would be sensitive to MTU parameters.

Methods

Stance phase of gait was simulated using a musculoskeletal model and computed muscle control algorithm. Optimal muscle fiber length, resting ankle angle, and tendon stiffness parameters were systematically changed to test these effects on plantarflexor metabolics, activation, and power. Dorsiflexor metabolics were also measured to determine the impact of the action of the antagonist muscle group.

Results and Significance

Plantarflexor metabolic demands were 1.5 and 2.7 times more sensitive to optimal fiber length and resting ankle angle, respectively, compared to the effect of tendon stiffness. Increased resting ankle plantarflexion induced a large passive plantarflexion moment during early stance, which required non-physiologic dorsiflexor contractions. Conversely, longer optimal fiber and more neutral resting ankle angles increased the shortening demands of the plantarflexors. These findings highlight the importance of carefully selecting MTU parameters when modeling gait with musculoskeletal models, especially in pathologic or high-performance athlete populations.



from #Audiology via ola Kala on Inoreader https://ift.tt/2Af0fAy
via IFTTT

Differential Effects of Hearing Impairment and Age on Electrophysiological and Behavioral Measures of Speech in Noise

Publication date: Available online 16 October 2018

Source: Hearing Research

Author(s): Tess K. Koerner, Yang Zhang

Abstract

Understanding speech in background noise is difficult for many listeners with and without hearing impairment (HI). This study investigated the effects of HI on speech discrimination and recognition measures as well as speech-evoked cortical N1-P2 and MMN auditory event-related potentials (AERPs) in background noise. We aimed to determine which AERP components can predict the effects of HI on speech perception in noise across adult listeners with and without HI. The data were collected from 18 participants with hearing thresholds ranging from within normal limits to bilateral moderate-to-severe sensorineural hearing loss. Linear mixed effects models were employed to examine how hearing impairment, age, stimulus type, and SNR listening condition affected neural and behavioral responses and what AERP components were correlated with effects of HI on speech-in-noise perception across participants. Significant effects of age were found on the N1-P2 but not on MMN, and significant effects of HI were observed on the MMN and behavioral measures. The results suggest that neural responses reflecting later cognitive processing of stimulus discrimination may be more susceptible to the effects of HI on the processing of speech in noise than earlier components that signal the sensory encoding of acoustic stimulus features. Objective AERP responses were also potential neural predictors of speech perception in noise across participants with and without HI, which has implications for the use of AERPs as a potential clinical tool for assessing speech perception in noise.



from #Audiology via ola Kala on Inoreader https://ift.tt/2AfxB2g
via IFTTT

Differential Effects of Hearing Impairment and Age on Electrophysiological and Behavioral Measures of Speech in Noise

Publication date: Available online 16 October 2018

Source: Hearing Research

Author(s): Tess K. Koerner, Yang Zhang

Abstract

Understanding speech in background noise is difficult for many listeners with and without hearing impairment (HI). This study investigated the effects of HI on speech discrimination and recognition measures as well as speech-evoked cortical N1-P2 and MMN auditory event-related potentials (AERPs) in background noise. We aimed to determine which AERP components can predict the effects of HI on speech perception in noise across adult listeners with and without HI. The data were collected from 18 participants with hearing thresholds ranging from within normal limits to bilateral moderate-to-severe sensorineural hearing loss. Linear mixed effects models were employed to examine how hearing impairment, age, stimulus type, and SNR listening condition affected neural and behavioral responses and what AERP components were correlated with effects of HI on speech-in-noise perception across participants. Significant effects of age were found on the N1-P2 but not on MMN, and significant effects of HI were observed on the MMN and behavioral measures. The results suggest that neural responses reflecting later cognitive processing of stimulus discrimination may be more susceptible to the effects of HI on the processing of speech in noise than earlier components that signal the sensory encoding of acoustic stimulus features. Objective AERP responses were also potential neural predictors of speech perception in noise across participants with and without HI, which has implications for the use of AERPs as a potential clinical tool for assessing speech perception in noise.



from #Audiology via ola Kala on Inoreader https://ift.tt/2AfxB2g
via IFTTT

Differential Effects of Hearing Impairment and Age on Electrophysiological and Behavioral Measures of Speech in Noise

Publication date: Available online 16 October 2018

Source: Hearing Research

Author(s): Tess K. Koerner, Yang Zhang

Abstract

Understanding speech in background noise is difficult for many listeners with and without hearing impairment (HI). This study investigated the effects of HI on speech discrimination and recognition measures as well as speech-evoked cortical N1-P2 and MMN auditory event-related potentials (AERPs) in background noise. We aimed to determine which AERP components can predict the effects of HI on speech perception in noise across adult listeners with and without HI. The data were collected from 18 participants with hearing thresholds ranging from within normal limits to bilateral moderate-to-severe sensorineural hearing loss. Linear mixed effects models were employed to examine how hearing impairment, age, stimulus type, and SNR listening condition affected neural and behavioral responses and what AERP components were correlated with effects of HI on speech-in-noise perception across participants. Significant effects of age were found on the N1-P2 but not on MMN, and significant effects of HI were observed on the MMN and behavioral measures. The results suggest that neural responses reflecting later cognitive processing of stimulus discrimination may be more susceptible to the effects of HI on the processing of speech in noise than earlier components that signal the sensory encoding of acoustic stimulus features. Objective AERP responses were also potential neural predictors of speech perception in noise across participants with and without HI, which has implications for the use of AERPs as a potential clinical tool for assessing speech perception in noise.



from #Audiology via ola Kala on Inoreader https://ift.tt/2AfxB2g
via IFTTT

Differential Effects of Hearing Impairment and Age on Electrophysiological and Behavioral Measures of Speech in Noise

Publication date: Available online 16 October 2018

Source: Hearing Research

Author(s): Tess K. Koerner, Yang Zhang

Abstract

Understanding speech in background noise is difficult for many listeners with and without hearing impairment (HI). This study investigated the effects of HI on speech discrimination and recognition measures as well as speech-evoked cortical N1-P2 and MMN auditory event-related potentials (AERPs) in background noise. We aimed to determine which AERP components can predict the effects of HI on speech perception in noise across adult listeners with and without HI. The data were collected from 18 participants with hearing thresholds ranging from within normal limits to bilateral moderate-to-severe sensorineural hearing loss. Linear mixed effects models were employed to examine how hearing impairment, age, stimulus type, and SNR listening condition affected neural and behavioral responses and what AERP components were correlated with effects of HI on speech-in-noise perception across participants. Significant effects of age were found on the N1-P2 but not on MMN, and significant effects of HI were observed on the MMN and behavioral measures. The results suggest that neural responses reflecting later cognitive processing of stimulus discrimination may be more susceptible to the effects of HI on the processing of speech in noise than earlier components that signal the sensory encoding of acoustic stimulus features. Objective AERP responses were also potential neural predictors of speech perception in noise across participants with and without HI, which has implications for the use of AERPs as a potential clinical tool for assessing speech perception in noise.



from #Audiology via ola Kala on Inoreader https://ift.tt/2AfxB2g
via IFTTT

Otoliths as object of EPR dosimetric research.

Related Articles

Otoliths as object of EPR dosimetric research.

Radiat Environ Biophys. 2018 Oct 15;:

Authors: Ivanov DV, Shishkina EA, Osipov DI, Starichenko VI, Bayankin SN, Zhukovsky MV, Pryakhin EA

Abstract
Otoliths are the organs which fish use for hearing and keeping balance. Otoliths are the most calcified tissues in the fish body. In contrast to bones, otoliths are not affected by remodeling and, therefore, they are expected to accumulate any dose from ionizing radiation during lifetime. Therefore, EPR dosimetry with fish otoliths could be an important tool for dose reconstruction in radiobiology and radioecology. It could also provide useful information remediation actions to de-contaminate waterbodies. Consequently, in the present study, otoliths of three contaminated fish species (roach (Rutilus rutilus), pike (Esox lucius) and perch (Perca Fluviatilis)) were examined with Electron Paramagnetic Resonance (EPR) spectroscopy. The fish were caught at storage reservoirs of liquid radioactive waste from Mayak PA and from the upper reach of the Techa River, which have been contaminated with different levels of radionuclide activity concentrations. It is shown that the radiation-induced EPR signal of otolith is stable and characterized by a linear dose response. However, the slope of the calibration curve (corresponding to the radiation sensitivity of the material) is not the same for different species; this may be caused by differences in mineralization. The reconstructed doses were found to be in the range from undetectable (in fish from the upper stream of the Techa River) up to 265 Gy (in roach from the most contaminated waterbody). In parallel, otoliths were measured with β-counter to detect 90Sr/90Y. Samples were also tested on the presence of alpha-emitters, but no alpha activity above background could be detected. However, a significant activity concentration of 90Sr was detected (from 1 × 101 to 2 × 104 Bq/g). The EPR doses measured correlated with the 90Sr activity concentration measured in the otolith samples.

PMID: 30324495 [PubMed - as supplied by publisher]



from #Audiology via ola Kala on Inoreader https://ift.tt/2RY5eMK
via IFTTT

Otolaryngology-Related Disorders in Underserved Populations, Otolaryngology Training and Workforce Considerations in North America.

Icon for Elsevier Science Icon for W.B. Saunders Related Articles

Otolaryngology-Related Disorders in Underserved Populations, Otolaryngology Training and Workforce Considerations in North America.

Otolaryngol Clin North Am. 2018 Jun;51(3):685-695

Authors: Westerberg BD, Lango MN

Abstract
In North America, underserved and vulnerable populations experience poorer health outcomes despite greater per capita health care expenditures. Biologic, behavioral, and socioeconomic factors lead to more advanced disease presentation that may necessitate disparate treatment. Additionally, vulnerable populations are more likely to obtain care from low-volume providers, and are more likely to receive inappropriate care. Disparities in care are exacerbated by the distribution of the physician workforce and limited participation by physicians in the care of vulnerable populations. Multipronged strategies are needed to ameliorate observed disparities in care.

PMID: 29482920 [PubMed - indexed for MEDLINE]



from #Audiology via ola Kala on Inoreader https://ift.tt/2EmU0Pg
via IFTTT

Otoliths as object of EPR dosimetric research.

Related Articles

Otoliths as object of EPR dosimetric research.

Radiat Environ Biophys. 2018 Oct 15;:

Authors: Ivanov DV, Shishkina EA, Osipov DI, Starichenko VI, Bayankin SN, Zhukovsky MV, Pryakhin EA

Abstract
Otoliths are the organs which fish use for hearing and keeping balance. Otoliths are the most calcified tissues in the fish body. In contrast to bones, otoliths are not affected by remodeling and, therefore, they are expected to accumulate any dose from ionizing radiation during lifetime. Therefore, EPR dosimetry with fish otoliths could be an important tool for dose reconstruction in radiobiology and radioecology. It could also provide useful information remediation actions to de-contaminate waterbodies. Consequently, in the present study, otoliths of three contaminated fish species (roach (Rutilus rutilus), pike (Esox lucius) and perch (Perca Fluviatilis)) were examined with Electron Paramagnetic Resonance (EPR) spectroscopy. The fish were caught at storage reservoirs of liquid radioactive waste from Mayak PA and from the upper reach of the Techa River, which have been contaminated with different levels of radionuclide activity concentrations. It is shown that the radiation-induced EPR signal of otolith is stable and characterized by a linear dose response. However, the slope of the calibration curve (corresponding to the radiation sensitivity of the material) is not the same for different species; this may be caused by differences in mineralization. The reconstructed doses were found to be in the range from undetectable (in fish from the upper stream of the Techa River) up to 265 Gy (in roach from the most contaminated waterbody). In parallel, otoliths were measured with β-counter to detect 90Sr/90Y. Samples were also tested on the presence of alpha-emitters, but no alpha activity above background could be detected. However, a significant activity concentration of 90Sr was detected (from 1 × 101 to 2 × 104 Bq/g). The EPR doses measured correlated with the 90Sr activity concentration measured in the otolith samples.

PMID: 30324495 [PubMed - as supplied by publisher]



from #Audiology via ola Kala on Inoreader https://ift.tt/2RY5eMK
via IFTTT

Otolaryngology-Related Disorders in Underserved Populations, Otolaryngology Training and Workforce Considerations in North America.

Icon for Elsevier Science Icon for W.B. Saunders Related Articles

Otolaryngology-Related Disorders in Underserved Populations, Otolaryngology Training and Workforce Considerations in North America.

Otolaryngol Clin North Am. 2018 Jun;51(3):685-695

Authors: Westerberg BD, Lango MN

Abstract
In North America, underserved and vulnerable populations experience poorer health outcomes despite greater per capita health care expenditures. Biologic, behavioral, and socioeconomic factors lead to more advanced disease presentation that may necessitate disparate treatment. Additionally, vulnerable populations are more likely to obtain care from low-volume providers, and are more likely to receive inappropriate care. Disparities in care are exacerbated by the distribution of the physician workforce and limited participation by physicians in the care of vulnerable populations. Multipronged strategies are needed to ameliorate observed disparities in care.

PMID: 29482920 [PubMed - indexed for MEDLINE]



from #Audiology via ola Kala on Inoreader https://ift.tt/2EmU0Pg
via IFTTT