Evaluation of the Efficacy of a Dual Variable Speed Compressor over a Single Fixed Speed Compressor.

Related Articles

Evaluation of the Efficacy of a Dual Variable Speed Compressor over a Single Fixed Speed Compressor.

J Am Acad Audiol. 2018 Nov 13;:

Authors: Kuk F, Slugocki C, Korhonen P, Seper E, Hau O

Abstract
BACKGROUND: It has been suggested that hearing-impaired listeners with a good working memory (WM) should be fitted with a compression system using short time constants (i.e., fast-acting compression [FAC]), whereas those with a poorer WM should be fitted with a longer time constant (i.e., slow-acting compression [SAC]). However, commercial hearing aids (HAs) seldom use a fixed speed of compression.
PURPOSE: The performance of a variable speed compression (VSC) system relative to a fixed speed compressor (FAC and SAC) on measures of speech intelligibility, recall, and subjective report of listening effort and tolerable time was evaluated. The potential interaction with the listeners' WM capacity (WMC) was also examined.
RESEARCH DESIGN: A double-blinded, repeated measures design.
STUDY SAMPLE: Seventeen HA wearers (16 with greater than one year HA experience) with a bilaterally symmetrical, mild to moderately severe sensorineural hearing loss participated in the study.
DATA COLLECTION AND ANALYSIS: Participants wore the study HAs at three compression speeds (FAC, SAC, and VSC). Each listener was evaluated on the Office of Research in Clinical Amplification-nonsense syllable test (NST) at 50 dB SPL (signal-to-noise ratio [SNR] = +15 dB), 65 dB SPL (SNR = +5 dB), 80 dB SPL (SNR = 0 dB), and a split (80 dB SPL-50 dB SPL) condition. Listeners were also evaluated on a Repeat Recall Test (RRT), where they had to repeat six short sentences (both high- and low-context sentences) after each was presented. Listeners recalled target words in all six sentences after they were presented. They also rated their listening effort and the amount of time they would tolerate listening under the specific condition. RRT sentences were presented at 75 dB SPL in quiet, as well as SNR = 0, 5, 10, and 15 dB. A Reading Span Test (RST) was also administered to assess listeners' WMC. Analysis of variance using RST scores as a covariate was used to examine differences in listener performance among compressor speeds.
RESULTS: Listener performance on the NST was similar among all three compression speeds at 50, 65, and 80 dB SPL. Performance with FAC was significantly better than SAC for the split condition; however, performance did not differ between FAC and VSC or between SAC and VSC. Performance on the NST was not affected by listeners' RST scores. On the RRT, there was no effect of compressor speed on measures of repeat, recall, listening effort, and tolerable time. However, VSC resulted in significantly lower (better) speech reception threshold at the 85% correct recognition criterion (SRT85) than FAC and SAC. Listener RST scores significantly affected recall performance on the RRT but did not affect SRT85, repeat, listening effort, or tolerable time.
CONCLUSION: These results suggest that the VSC, FAC, and SAC yield similar performance in most but not all test conditions. FAC outperforms SAC, where the stimulus levels change abruptly (i.e., split condition). The VSC yields a lower SRT85 than a fixed compression speed at a moderately high level with a favorable SNR. There is no interaction between compression speed and the participants' WMC.

PMID: 30420004 [PubMed - as supplied by publisher]

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Evaluation of the Efficacy of a Dual Variable Speed Compressor over a Single Fixed Speed Compressor.

Related Articles

Evaluation of the Efficacy of a Dual Variable Speed Compressor over a Single Fixed Speed Compressor.

J Am Acad Audiol. 2018 Nov 13;:

Authors: Kuk F, Slugocki C, Korhonen P, Seper E, Hau O

Abstract
BACKGROUND: It has been suggested that hearing-impaired listeners with a good working memory (WM) should be fitted with a compression system using short time constants (i.e., fast-acting compression [FAC]), whereas those with a poorer WM should be fitted with a longer time constant (i.e., slow-acting compression [SAC]). However, commercial hearing aids (HAs) seldom use a fixed speed of compression.
PURPOSE: The performance of a variable speed compression (VSC) system relative to a fixed speed compressor (FAC and SAC) on measures of speech intelligibility, recall, and subjective report of listening effort and tolerable time was evaluated. The potential interaction with the listeners' WM capacity (WMC) was also examined.
RESEARCH DESIGN: A double-blinded, repeated measures design.
STUDY SAMPLE: Seventeen HA wearers (16 with greater than one year HA experience) with a bilaterally symmetrical, mild to moderately severe sensorineural hearing loss participated in the study.
DATA COLLECTION AND ANALYSIS: Participants wore the study HAs at three compression speeds (FAC, SAC, and VSC). Each listener was evaluated on the Office of Research in Clinical Amplification-nonsense syllable test (NST) at 50 dB SPL (signal-to-noise ratio [SNR] = +15 dB), 65 dB SPL (SNR = +5 dB), 80 dB SPL (SNR = 0 dB), and a split (80 dB SPL-50 dB SPL) condition. Listeners were also evaluated on a Repeat Recall Test (RRT), where they had to repeat six short sentences (both high- and low-context sentences) after each was presented. Listeners recalled target words in all six sentences after they were presented. They also rated their listening effort and the amount of time they would tolerate listening under the specific condition. RRT sentences were presented at 75 dB SPL in quiet, as well as SNR = 0, 5, 10, and 15 dB. A Reading Span Test (RST) was also administered to assess listeners' WMC. Analysis of variance using RST scores as a covariate was used to examine differences in listener performance among compressor speeds.
RESULTS: Listener performance on the NST was similar among all three compression speeds at 50, 65, and 80 dB SPL. Performance with FAC was significantly better than SAC for the split condition; however, performance did not differ between FAC and VSC or between SAC and VSC. Performance on the NST was not affected by listeners' RST scores. On the RRT, there was no effect of compressor speed on measures of repeat, recall, listening effort, and tolerable time. However, VSC resulted in significantly lower (better) speech reception threshold at the 85% correct recognition criterion (SRT85) than FAC and SAC. Listener RST scores significantly affected recall performance on the RRT but did not affect SRT85, repeat, listening effort, or tolerable time.
CONCLUSION: These results suggest that the VSC, FAC, and SAC yield similar performance in most but not all test conditions. FAC outperforms SAC, where the stimulus levels change abruptly (i.e., split condition). The VSC yields a lower SRT85 than a fixed compression speed at a moderately high level with a favorable SNR. There is no interaction between compression speed and the participants' WMC.

PMID: 30420004 [PubMed - as supplied by publisher]

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AGE-RELATED CHANGES IN UPPER BODY CONTRIBUTION TO BRAKING FORWARD LOCOMOTION IN WOMEN

Publication date: Available online 13 November 2018

Source: Gait & Posture

Author(s): Lorenzo Rum, Luca Laudani, Giuseppe Vannozzi, Andrea Macaluso

Abstract

Introduction

Gait termination is a transitory task that requires the lower body to produce braking forces and inhibit forward propulsion. However, it is still unknown whether the upper body plays an active role in braking of gait and whether this mechanism is impaired with ageing.

RESEARCH QUESTION: Do older women exhibit an impaired control of upper body segments during gait termination with respect to young women?

Methods

Ten young and 10 older women performed three gait termination trials at comfortable speed while fixing the gaze on a visual target. A 3D motion analysis system was used to measure head, trunk and pelvis angular displacement and velocity, and estimate neck, waist and hip moments through Plug-in Gait modeling. Cross-correlation analysis of kinematic waveforms between paired adjacent segments (head-trunk and trunk-pelvis) was performed to investigate upper body coordination. Surface EMG activity of erector spinae (L3), sternocleidomastoid and neck extensor muscles was recorded. Statistics was carried out by MANOVA.

Results

Older participants exhibited delayed peak extensor torques of neck, waist and hip compared to young participants, along with lower progression speed. Both groups showed a slight flexion of the trunk counteracted by a backward tilt of head and pelvis during braking. In addition, older women displayed a peculiar upper body coordination pattern, with the head coupling with trunk motion, as shown by cross-correlation. Older women displayed shorter lumbar erector spinae onset latency relative to last heel contact than young (16 ± 68 ms vs 92 ± 37 ms).

Significance

The upper body plays an active role in the braking of gait and this mechanism is impaired in older women. Moreover, the age-related coupling of head and trunk motion may produce an unbalancing effect on whole-body stability during the braking mechanism, thus leading to a higher risk of falls.

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Self-Selected walking speed increases when individuals are aware of being recorded

Publication date: Available online 13 November 2018

Source: Gait & Posture

Author(s): Laura A Hutchinson, Marcus J Brown, Kevin J Deluzio, Alan R. De Asha

Abstract

Background

Typical gait data collections consist of discrete walking trials where participants are aware when data are being recorded. Anecdotally, some investigators have reported that participants often walk differently between trials or before or after data collection compared to when they know they are being recorded. In addition, walking speed, which affects a number of gait variables, is known to be different when individuals complete discrete and continuous walking trials.

Research question

The purpose of this study was to determine whether changes in walking speed occurred as a result of participants being aware, versus unaware that data were being recorded, during both discrete and continuous walking trials.

Methods

Kinematic data were collected for twenty two individuals walking continuous trials or discrete trials, while they were both aware and unaware of being recorded. Comparisons of walking speeds were made between groups (continuous walking; discrete trials) and awareness of being recorded (aware; unaware) using a two way ANOVA

Results

The results indicated that participants walked significantly faster during discrete trials when they were aware that data were being recorded compared to when they were unaware. However, when they walked continuously their walking speed was not affected by their awareness.

Significance

The results suggest that awareness of data collection, and the type of protocol used during data collection, affect an individual’s walking speed during gait analysis. Therefore, care should be taken when determining gait analysis protocols where variables are sensitive to walking speeds.

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AGE-RELATED CHANGES IN UPPER BODY CONTRIBUTION TO BRAKING FORWARD LOCOMOTION IN WOMEN

Publication date: Available online 13 November 2018

Source: Gait & Posture

Author(s): Lorenzo Rum, Luca Laudani, Giuseppe Vannozzi, Andrea Macaluso

Abstract

Introduction

Gait termination is a transitory task that requires the lower body to produce braking forces and inhibit forward propulsion. However, it is still unknown whether the upper body plays an active role in braking of gait and whether this mechanism is impaired with ageing.

RESEARCH QUESTION: Do older women exhibit an impaired control of upper body segments during gait termination with respect to young women?

Methods

Ten young and 10 older women performed three gait termination trials at comfortable speed while fixing the gaze on a visual target. A 3D motion analysis system was used to measure head, trunk and pelvis angular displacement and velocity, and estimate neck, waist and hip moments through Plug-in Gait modeling. Cross-correlation analysis of kinematic waveforms between paired adjacent segments (head-trunk and trunk-pelvis) was performed to investigate upper body coordination. Surface EMG activity of erector spinae (L3), sternocleidomastoid and neck extensor muscles was recorded. Statistics was carried out by MANOVA.

Results

Older participants exhibited delayed peak extensor torques of neck, waist and hip compared to young participants, along with lower progression speed. Both groups showed a slight flexion of the trunk counteracted by a backward tilt of head and pelvis during braking. In addition, older women displayed a peculiar upper body coordination pattern, with the head coupling with trunk motion, as shown by cross-correlation. Older women displayed shorter lumbar erector spinae onset latency relative to last heel contact than young (16 ± 68 ms vs 92 ± 37 ms).

Significance

The upper body plays an active role in the braking of gait and this mechanism is impaired in older women. Moreover, the age-related coupling of head and trunk motion may produce an unbalancing effect on whole-body stability during the braking mechanism, thus leading to a higher risk of falls.

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Self-Selected walking speed increases when individuals are aware of being recorded

Publication date: Available online 13 November 2018

Source: Gait & Posture

Author(s): Laura A Hutchinson, Marcus J Brown, Kevin J Deluzio, Alan R. De Asha

Abstract

Background

Typical gait data collections consist of discrete walking trials where participants are aware when data are being recorded. Anecdotally, some investigators have reported that participants often walk differently between trials or before or after data collection compared to when they know they are being recorded. In addition, walking speed, which affects a number of gait variables, is known to be different when individuals complete discrete and continuous walking trials.

Research question

The purpose of this study was to determine whether changes in walking speed occurred as a result of participants being aware, versus unaware that data were being recorded, during both discrete and continuous walking trials.

Methods

Kinematic data were collected for twenty two individuals walking continuous trials or discrete trials, while they were both aware and unaware of being recorded. Comparisons of walking speeds were made between groups (continuous walking; discrete trials) and awareness of being recorded (aware; unaware) using a two way ANOVA

Results

The results indicated that participants walked significantly faster during discrete trials when they were aware that data were being recorded compared to when they were unaware. However, when they walked continuously their walking speed was not affected by their awareness.

Significance

The results suggest that awareness of data collection, and the type of protocol used during data collection, affect an individual’s walking speed during gait analysis. Therefore, care should be taken when determining gait analysis protocols where variables are sensitive to walking speeds.

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