***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 
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    ***EXAMPLES*** 
    Input: BACKGROUND Little is known about quality of life after the use of specific types of hearing aids , so it is difficult to determine whether technologies such as programmable circuits and directional microphones are worth the added expense . OBJECTIVE To compare the effectiveness of an assistive listening device , a nonprogrammable nondirectional microphone hearing aid , with that of a programmable directional microphone hearing aid against the absence of amplification . DESIGN R and omized controlled trial . SETTING Audiology clinic at the VA Puget Sound Health Care System , Seattle , Wash. PATIENTS Sixty veterans with bilateral moderate to severe sensorineural hearing loss completed the trial . Half the veterans ( n = 30 ) had hearing loss that the Veterans Affairs clinic determined was rated as " service connected , " which meant that they were eligible for Veterans Affairs-issued hearing aids . INTERVENTION Veterans with non-service-connected hearing loss , who were ineligible for Veterans Affairs-issued hearing aids , were r and omly assigned to no amplification ( control arm ) or to receive an assistive listening device .  Veterans with service-connected loss were r and omly assigned to receive either the nonprogrammable hearing aid that is routinely issued ( " conventional " ) or a programmable aid with a directional microphone ( " programmable " ) . MAIN OUTCOME MEASURES Hearing-related quality of life , self-rated communication ability , adherence to use , and willingness to pay for the amplification devices ( measured 3 months after fitting ) . RESULTS Clear distinctions were observed between all 4 arms . The mean improvement in hearing-related quality of life ( Hearing H and icap Inventory for the Elderly ) scores was small for control patients ( 2.2 points ) and patients who received an assistive listening device ( 4.4 points ) , excellent for patients who received a conventional device ( 17.4 points ) , and substantial for patients who received a programmable device ( 31.1 points ) ( P<.001 by the analysis of variance test ) . Qualitative analyses of free-text diary entries , self-reported communication ability ( Abbreviated Profile of Hearing Aid Benefit ) scores , adherence to hearing aid use , and willingness to pay for replacement devices showed similar trends . CONCLUSIONS A programmable hearing aid with a directional microphone had the highest level of effectiveness in the veteran population . A nonprogrammable hearing aid with an omnidirectional microphone was also effective compared with an assistive listening device or no amplification This investigation examined whether speech intelligibility in noise can be improved using a new , binaural broadb and hearing instrument system .  Participants were 36 adults with symmetrical , sensorineural hearing loss ( 18 experienced hearing instrument users and 18 without prior experience ) . Participants were fit binaurally in a planned comparison , r and omized crossover design study with binaural broadb and hearing instruments and advanced digital hearing instruments . Following an adjustment period with each device , participants underwent two  speech-in-noise tests : the  QuickSIN and the Hearing in Noise Test ( HINT ) . Results suggested significantly better performance on the QuickSIN and the HINT measures with the binaural broadb and hearing instruments , when compared with the advanced digital hearing instruments and unaided , across and within all noise conditions A prospect i ve trial of hearing aid provision was undertaken to define factors which might be used to allow hearing aids to be fitted optimally . Patients referred for the provision of a hearing aid  were studied prospect ively at each of five visits when they were question ed by means of a proforma . Fifty-six patients completed the trial and gave adequate responses for analysis . No audiometric or symptomatic criteria were found to be of use in predicting the final choice of hearing aid combination . It may be that initial sequential monaural aiding leads to a higher uptake of binaural aids in the long term . Patients valued multiple visits to the clinic and sequential trials of monaural aiding , the majority felt that binaural aids should be tried The UK National Study of Hearing set out to ascertain the prevalence of hearing impairments of various magnitudes , the prevalence of ear disease and the associated risk factors , and to estimate the percentage of individuals requiring some form of management . A stratified sample of 2708 British adults , aged 18 - 80 years , was chosen from a sample of 48,313 adults , r and omly selected from the electoral roll , for a full otological and audiological assessment . This paper deals primarily with the middle ear results . Otoscopically , 2.6 % of British adults had inactive and 1.5 % had active chronic otitis media . This condition was more common in older individuals and in those in manual occupations . For this purpose , presumptive otosclerosis was defined as a conductive component to the impairment ( average air bone gap over 0.5 , 1 and 2 kHz of 15 dB or greater ) and with an intact tympanic membrane . The population prevalence for presumptive otosclerosis was 2.1 % , for healed OM 1.7 % and for Eustachian tube dysfunction 0.9 % . This prevalence of otosclerosis was higher in those over 40 years , but only in those with air bone gaps of 30 dB or greater were women more likely to have the condition than men , by a factor of three . At most , 20 % of individuals with any of the above middle ear conditions will have had ear surgery BACKGROUND The decision to fit one or two hearing aids in individuals with binaural hearing loss has been debated for years . Although some 78 % of U.S. hearing aid fittings are binaural ( Kochkin , 2010 ) , Walden and Walden ( 2005 ) presented data showing that 82 % ( 23 of 28 patients ) of their sample obtained significantly better speech recognition in noise scores when wearing one hearing aid as opposed to two . PURPOSE To conduct two new experiments to fuel the monaural/binaural debate . The first experiment was a replication of Walden and Walden ( 2005 ) , whereas the second experiment examined the use of binaural cues to improve speech recognition in noise . RESEARCH DESIGN A repeated measures experimental design . STUDY SAMPLE Twenty veterans ( aged 59 - 85 yr ) , with mild to moderately severe binaurally symmetrical hearing loss who wore binaural hearing aids were recruited from the Audiology Department at the Bay Pines VA Healthcare System . DATA COLLECTION AND ANALYSIS Experiment 1 followed the procedures of the Walden and Walden study , where signal-to-noise ratio ( SNR ) loss was measured using the  Quick Speech-in-Noise ( QuickSIN ) test on participants who were aided with their current hearing aids . Signal and noise were presented in the sound booth at 0 ° azimuth under five test conditions : ( 1 ) right ear aided , ( 2 ) left ear aided , ( 3 ) both ears aided , ( 4 ) right ear aided , left ear plugged , and ( 5 ) unaided . The opposite ear in ( 1 ) and ( 2 ) was left open . In Experiment 2 , binaural Knowles Electronics Manikin for Acoustic Research ( KEMAR ) manikin recordings made in Lou Malnati 's pizza restaurant during a busy period provided a typical real-world noise , while prerecorded target sentences were presented through a small loudspeaker located in front of the KEMAR manikin . Subjects listened to the result ing binaural recordings through insert earphones under the following four conditions : ( 1 ) binaural , ( 2 ) diotic , ( 3 ) monaural left , and ( 4 ) monaural right . RESULTS Results of repeated measures ANOVAs demonstrated that the best speech recognition in noise performance was obtained by most participants with both ears aided in Experiment 1 and in the binaural condition in Experiment 2 . CONCLUSIONS In both experiments , only 20 % of our subjects did better in noise with a single ear , roughly similar to the earlier Jerger et al ( 1993 ) finding that 8 - 10 % of elderly hearing aid users preferred one hearing aid The primary aim of this research was to evaluate the validity , efficacy , and generalization of principles underlying a sound therapy-based treatment for promoting expansion of the auditory dynamic range ( DR ) for loudness . The basic sound therapy principles , originally devised for treatment of hyperacusis among patients with tinnitus , were evaluated in this study in a target sample of unsuccessfully fit and /or problematic prospect i ve hearing aid users with diminished DRs ( owing to their elevated audiometric thresholds and reduced sound tolerance ) . Secondary aims included : ( 1 ) delineation of the treatment contributions from the counseling and sound therapy components to the full-treatment protocol and , in turn , the isolated treatment effects from each of these individual components to intervention success ; and ( 2 ) characterization of the respective dynamics for full , partial , and control treatments . Thirty-six participants with bilateral sensorineural hearing losses and reduced DRs , which affected their actual or perceived ability to use hearing aids , were enrolled in and completed a placebo-controlled ( for sound therapy ) r and omized clinical trial . The 2 × 2 factorial trial design was implemented with or without various assignments of counseling and sound therapy . Specifically , participants were assigned r and omly to one of four treatment groups ( nine participants per group ) , including : ( 1 ) group 1-full treatment achieved with scripted counseling plus sound therapy implemented with binaural sound generators ; ( 2 ) group 2-partial treatment achieved with counseling and placebo sound generators ( PSGs ) ; ( 3 ) group 3-partial treatment achieved with binaural sound generators alone ; and ( 4 ) group 4-a neutral control treatment implemented with the PSGs alone . Repeated measurements of categorical loudness judgments served as the primary outcome measure . The full-treatment categorical-loudness judgments for group 1 , measured at treatment termination , were significantly greater than the corresponding pretreatment judgments measured at baseline at 500 , 2,000 , and 4,000 Hz . Moreover , increases in their " uncomfortably loud " judgments ( ∼12 dB over the range from 500 to 4,000 Hz ) were superior to those measured for either of the partial-treatment groups 2 and 3 or for control group 4 . Efficacy , assessed by treatment-related criterion increases ≥ 10 dB for judgments of uncomfortable loudness , was superior for full treatment ( 82 % efficacy ) compared with that for either of the partial treatments ( 25 % and 40 % for counseling combined with the placebo sound therapy and sound therapy alone , respectively ) or for the control treatment ( 50 % ) . The majority of the group 1 participants achieved their criterion improvements within 3 months of beginning treatment . The treatment effect from sound therapy was much greater than that for counseling , which was statistically indistinguishable in most of our analyses from the control treatment . The basic principles underlying the full-treatment protocol are valid and have general applicability for exp and ing the DR among individuals with sensorineural hearing losses , who may often report aided loudness problems . The positive full-treatment effects were superior to those achieved for either counseling or sound therapy in virtual or actual isolation , respectively ; however , the delivery of both components in the full-treatment approach was essential for an optimum treatment outcome We present an experimental design for the evaluation of  therapeutic preferences among well established similar modes of therapy . The measure of the degree of preference is based on clinical decisions to continue or discontinue the current treatment at each patient visit . Such a trial simulates decision-making in ordinary clinical practice , while adhering to the scientific principles of experimental design , and it alleviates some of the ethical problems inherent in r and omized allocation of a treatment for a period of fixed length in conventional control trials . We discuss the design and methods of analysis and illustrate their application with data from a trial comparing three alternative drug treatments for chronic asthma . Such clinical trials provide a mechanism for examining concordance between the relative efficacy of treatments predicted from conventional controlled clinical trials and their ultimate performance in ordinary clinical practice , expressed in terms of therapeutic preferences Using screening question naires we were able to detect individuals aged 50–65 years with hearing disability in a general practice population . Those who had better ear hearing levels of 30 dB or worse were invited to take place in a cross-over study comparing the acceptability of a monaural or binaural hearing-aid fitting . Fifty-five per cent ultimately opted for a binaural fitting and had greater hearing disability and worse mean hearing levels than those who opted for a monaural fitting . They made their choice for acoustical reasons , particularly on the basis of improved localization ability Objectives : Most practitioners believe that use of two hearing aids is the ideal fitting for adults with bilateral symmetrical hearing loss . However , previous research has consistently shown that a substantial proportion of these patients actually prefer to use only one hearing aid . This study explored whether this pattern of preferences is seen with technologically advanced hearing aids . In addition , a selection of variables that were available prefitting were used to attempt to predict which patients will prefer one hearing aid rather than two . Design : The study was design ed as a 12-week field trial including structured and unstructured use of one and two hearing aids .  Ninety-four subjects with mild to moderate bilaterally symmetrical hearing loss were bilaterally fit with 2005–2007 era hearing aids .  Potential predictors included demographic , audiometric , auditory lifestyle , personality , and binaural processing variables . After the field trial , each subject stated his or her preference for one or two hearing aids and completed three self-report outcome question naires for their preferred fitting . Results : Previous research was confirmed with modern technology hearing aids : after the field trial , 46 % of the subjects preferred to use one hearing aid rather than two . Subjects who preferred two hearing aids tended to report better real-world outcomes than those who preferred one . Subjects who reported more hearing problems in daily life  , who experienced more binaural loudness summation , and whose ears were more equivalent in dichotic listening were more likely to prefer to use two hearing aids . Contrary to conventional wisdom ( ideas that are generally 
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We were unable to pool data from the four studies and the very low quality of the evidence leads us to conclude that we do not know if people with hearing loss have a preference for one aid or two .
Similarly , we do not know if hearing-specific health-related quality of life , or any of our other outcomes , are better with bilateral or unilateral aids