***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: In this clinical study , 110 patients seen at three different clinical facilities were fit binaurally with linear , in-the-canal ( ITC ) hearing aids .  All patients were new hearing aid users . Each of the hearing aids was equipped with an adjustable control that could be set by one of the audiologists ( Audiologist A ) at each site to convert it from a linear instrument to an experimental nonlinear one with automatic reduction of low-frquency gain at high input levels ( or base increase at low levels , BILL ) . Both the patient and the audiologist performing the outcome testing at each site ( Audiologist B ) were blind as to the present setting of the hearing aid . Each participant was enrolled in the study for a total of 12 weeks , with the hearing aid set to either the linear or BILL-processing mode of operation for the first 8 weeks and the opposite setting for a subsequent 4-week period . In summary , this was a prospect i ve , doubleblind , crossover study of 110 new hearing aid users . Outcome measures focused on hearing-aid benefit and included both objective and subjective measures . Objective measures were derived from scores on the Northwestern University Auditory Test NO . 6 ( NU-6 ) and the Connected Speech Test ( CST ) obtained for all possible combinations of two speech presentation levels ( 60 and 75 dB SPL ) two types of background noise ( cafeteria noise and multitalker babble ) , and two signal-to-noise ratios ( + 5 and + 10 dB ) . Subjective outcome measures included magnitude estimation of listening effort ( MELE ) , the abbreviated form of the Hearing Aid Performance Inventory ( HAPI ) , and estimations of hearing-aid usage based on daily-use logs kept by the participants . All of these measures were used to evaluate the benefit provided by linear amplification and the benefit result ing from the experimental BILL processing . Participant preferences for the experimental BILL-processing scheme or linear processing were also examined by using a paired-comparison task at the end of the study . Results were analyzed separately for three subgroups of patients ( mild , moderate , severe ) formed on the basis of their average hearing loss at 500 , 1000 , 2000 , and 4000 Hz . In all three subgroups , significant improvement in performance was observed for linear amplification and for BILL processing when compared to unaided performance . There were no significant differences in aided performance , however , between linear processing and the experimental BILL processing PURPOSE Using a dual-task paradigm , 2 experiments ( Experiments 1 and 2 ) were conducted to assess differences in the amount of listening effort expended to underst and speech in noise in audiovisual ( AV ) and audio-only ( A-only ) modalities . Experiment 1 had equivalent noise levels in both modalities , and Experiment 2 equated speech recognition performance levels by increasing the noise in the AV versus A-only modality . METHOD Sixty adults were r and omly assigned to Experiment 1 or Experiment 2 . Participants performed speech and tactile recognition tasks separately ( single task ) and concurrently ( dual task ) . The speech tasks were performed in both modalities . Accuracy and reaction time data were collected as well as ratings of perceived accuracy and effort . RESULTS In Experiment 1 , the AV modality speech recognition was rated as less effortful , and accuracy scores were higher than A only . In Experiment 2 , reaction times were slower , tactile task performance was poorer , and listening effort increased , in the AV versus the A-only modality . CONCLUSIONS At equivalent noise levels , speech recognition performance was enhanced and subjectively less effortful in the AV than A-only modality . At equivalent accuracy levels , the dual-task performance decrements ( for both tasks ) suggest that the noisier AV modality was more effortful than the A-only modality Cognitive task-evoked pupillary responses reliably index information-processing loads . However , previous studies have reported inconsistent findings regarding the nature of the pupillary response when processing dem and s approach or exceed available processing re sources . This condition was examined in 22 normal undergraduates by using pupillometric recordings during a digit span recall task , with 5 ( low load ) , 9 ( moderate load ) , and 13 ( excessive load ) digits per string .  Pupillary responses increased systematic ally with increased processing load ( to-be-recalled digits ) until the limit of available re sources ( memory capacity of 7 + /- 2 digits ) , when they reached asymptote and then declined with re source overload ( > 9 digits ) . These findings suggest that pupillary responses increase systematic ally with increased processing dem and s that are below re source limits , change little during active processing at or near re source limits , and begin to decline when processing dem and s exceed available re sources Abstract Objective : Single channel noise reduction has been well investigated and seems to have reached its limits in terms of speech intelligibility improvement , however , the quality of such schemes can still be advanced . This study tests to what extent novel model-based processing schemes might improve performance in particular for non-stationary noise conditions . Design : Two prototype model-based algorithms , a speech-model-based , and a auditory-model-based algorithm were compared to a state-of-the-art non-parametric minimum statistics algorithm . A speech intelligibility test , preference rating , and listening effort scaling were performed . Additionally , three objective quality measures for the signal , background , and overall distortions were applied . For a better comparison of all algorithms , particular attention was given to the usage of the similar Wiener-based gain rule . Study sample : The perceptual investigation was performed with fourteen hearing-impaired subjects . Results : The results revealed that the non-parametric algorithm and the auditory model-based algorithm did not affect speech intelligibility , whereas the speech-model-based algorithm slightly decreased intelligibility . In terms of subjective quality , both model-based algorithms perform better than the unprocessed condition and the reference in particular for highly non-stationary noise environments . Conclusion : Data support the hypothesis that model-based algorithms are promising for improving performance in non-stationary noise conditions Speech recognition and cognitive functions important for speech underst and ing were evaluated by objective measures and by scores of perceived effort , with and without hearing aids . The tests were performed in silence , and with background conditions of speech spectrum r and om noise and ordinary speech .  One young and one elderly group of twelve hearing-impaired subjects each participated .  Hearing aid use improved speech recognition in silence ( 7 dB ) and in the condition with speech as background ( 2.5 dB S/N ) , but did not change the perceived effort scores . In the cognitive tests no hearing aid benefit was seen in objective measures , while there was an effect of hearing aid use in scores of perceived effort , subjects reported less effort . There were no age effects on hearing aid benefit . In conclusion , hearing aid use may result in reduced effort in listening tasks that is not associated with improvement in objective scores The purpose of this study was to determine the impact of a digital noise reduction ( DNR ) scheme implemented in a current commercial hearing aid . In a double-blinded design , three conditions of onset time ( 4 , 8 , 16 seconds ) were r and omly assigned to the 25 subjects , plus one condition wherein the noise-reduction feature was disengaged . Subsequently , a fifth trial/condition , wherein the subject had access to three memories in which the different onsets were programmed , was carried out . For each of the five conditions , the subjects had an at-home trial , prior to obtaining self-report measures . Laboratory measures of speech perception showed no effect of the DNR , with or without the provision of visual cues . Laboratory-based ratings of ease of listening showed  DNR-on ( all onset times ) to be rated significantly better than DNR-off ; for ratings of listening comfort , the 4-second onset time was rated significantly lower ( poorer ) than the 8-second onset or the DNR-off condition ; for ratings of sound quality , DNR-on or -off had no differential effect . Self-report measures indicated significantly higher aversiveness in the DNR-off condition compared to the pre-test 
    Output:
    
For all other studies , the evidence across studies failed to reveal consistent effects on listening effort .
Conclusion : In summary , we could only identify scientific evidence from physiological measurement methods , suggesting that hearing impairment increases listening effort during speech perception ( Q1 ) .
There was no scientific , finding across studies indicating that hearing aid amplification decreases listening effort ( Q2 ) .