Central deafness: a review of past and current perspectives

Abstract

Objective: The purpose of this review was to describe and differentiate clinical syndromes caused by lesions of the central auditory nervous system (CANS).

Design: Relevant literature was identified through Pubmed and Google Scholar searches using the key terms: central deafness, auditory agnosia, word deafness and cortical deafness. Given the authors’ intent to review past and current perspectives on central deafness, no publication date range was imposed.

Study sample: The review is organised around complete central deafness (CCD), central deafness (CD), word deafness and nonverbal agnosia (NVA), including anatomy and pathophysiology, symptom profile and audiological findings. Four case studies are presented to demonstrate the clinical correlates of CD.

Conclusions: Central deafness is a rare condition typically resulting from bilateral compromise of the CANS. The closer to the auditory cortex bilateral lesions are located, the greater the probability of CD. A variety of symptoms present with or appear subsequent to CD, including tinnitus, hallucinations, voice changes and hypersensitivity to sounds (if heard by the patient), as well as diverse neurological symptoms depending on the non-auditory areas of the brain that may also be involved. Thorough and appropriate audiological testing is critical to accurately diagnose CD and its variants.     

Early discovery of hearing impairment: A Critical evaluation of the BOEL test

The BOEL test was originally devised for the early discovery of communication disorders in infants. The sound stimuli employed for hearing testing have been calibrated and standardized and any deviation from normal hearing responses to these stimuli indicate a hearing impairment.

Since 1971 the BOEL screening program has been applied experimentally in a number of child health centers in Stockholm. Up to 1975, more than 30 000 infants have been examined and approximately 5% have not responded fully regarding visual or tactile attention, auditory, motor or mental functions or social contact. The results of the audiological follow-up are reported.

Application of the BOEL hearing subtest proved very effective. It is pointed out that the BOEL test covers not only hearing defects but also other communication malfunctions and as such it is a more useful technique than simple hearing screening methods.     

Management of unilateral hearing loss

ObjectiveA representative sample of literature regarding unilateral hearing loss (UHL) was reviewed to provide evidence of the effects of UHL and the intervention options available for children with UHL. Considerations during the assessment and management of children with UHL are illustrated using case illustrations.MethodResearch articles published from 2013 to 2015 were searched in the PubMed database using the keywords “unilateral hearing loss”. Articles from 1950 to 2013 were included from a previous literature review on minimal hearing loss [1]. A retrospective review of charts of 14 children with UHL was also conducted.ResultsThe evidence indicates that children with UHL are more likely to have structural anomalies of the inner ear; may face challenges in six different domains, and have six intervention options available. Evidence also indicates that although some children appear to exhibit no delays or difficulties, others have significant challenges, some of which continue into adulthood.ConclusionsChildren with UHL have to be treated on a case-by-case basis. Parent education regarding UHL, its effects, and all available management options is critical so they can make informed decisions. Close monitoring and good communication between professionals in different domains is crucial in order to minimize the potential negative effects of UHL.     

Post-lingual deafness: benefits of cochlear implants vs. conventional hearing aids

The technological advances in cochlear implants and processing strategies have enabled subjects affected by severe to profound hearing loss to hear sounds and recognize speech in various different degrees. The variability of hearing outcomes in subjects with post-lingual deafness has been significant and cochlear implant indications have been extended to include an ever larger population.ObjectiveThis paper aims to look into the groups of post-lingual deafness patients to find where cochlear implants have yielded better outcomes than conventional hearing aids.Materials and MethodsReview the literature available on databases SciELO, Cochrane, MEDLINE, and LILACS-BIREME. The publications selected for review were rated as A or B on evidence strength on the day of the review. Their authors analyzed and compared hearing aids and cochlear implants in populations of post-lingually deaf patients. Study Design: Systematic review.ResultsEleven out of the 2,169 papers searched were found to be pertinent to the topic and were rated B for evidence strength. Six studies were prospective cohort trials, four were cross-sectional studies and one was a clinical trial.ConclusionThe assessment done on the benefits yielded by post-lingually deaf subjects from cochlear implants showed that they are effective and provide for better results than conventional hearing aids.     

Evaluation of auditory processing and phonemic discrimination in children with normal and disordered phonological development

Auditory processing and phonemic discrimination are essential for communication. Type of study: Retrospective.AimTo evaluate auditory processing and phonemic discrimination in children with normal and disordered phonological development.Material and MethodsAn evaluation of 46 children was carried out: 22 had phonological disorders and 24 had normally developing speech. Diotic, monotic and dichotic tests were applied to assess auditory processing and a test to evaluate phonemic discrimination abilities.DesignCross-sectional, contemporary.ResultsThe values of normally-developing children were within the normal range in all auditory processing tests; these children attained maximum phonemic discrimination test scores. Children with phonological disorders performed worse in the latter, and presented disordered auditory processing.ConclusionAuditory processing and phonemic discrimination in children with phonological disorders are altered.     

Applicability of the P300 frequency pattern test to assess auditory processing

Temporal ordering and auditory attention are important skills in information processing, being evaluated by a behavioral test, as the frequency pattern test (FPT) in temporal ordering (TO) and electrophysiological testing, as the P300 in auditory attention.ObjectiveTo analyze the applicability of FPT and P300 as testing for auditory processing.MethodWe performed an integrative literature review, with papers that met the inclusion criteria, using the MedLine, LILACS and SciELO databases, with the keywords: hearing attention, P300 evoked potential, P300 and electrophysiology, temporal ordering, processing and FPT. We found 13 papers concerning the use of the TPF and 16 regarding the use of P300.ResultsThe TPF was the most used test in the evaluation of TO, presented in a diotic way in individuals with language disorders, musicians, blind people, rural workers and different age groups. The P300 is used in the frequency of 1000 Hz in the frequent stimulus and 2000 Hz for the rare stimulus, applicable in individuals of both genders, different age groups, and in patients with Down syndrome, liver cirrhosis, AIDS and Sleep Apnea Syndrome.ConclusionThe FPT and P300 are efficient instruments used to assess the intended skills.     

Performance of hearing skills in children with auditory neuropathy spectrum disorder using cochlear implant: a systematic review

IntroductionCurrently, there are no doubts about the benefits of cochlear implants for the development of children with severe or profound hearing loss. However, there is still no consensus among researchers and professionals regarding the benefits for the improvement of hearing skills in children with auditory neuropathy spectrum disorder using cochlear implants.ObjectiveReview the available evidence in the literature to answer the following: “What is the performance of hearing skills in children with auditory neuropathy spectrum disorder using cochlear implants?”MethodsSystematic review of the literature through electronic database consultation, considering publications in the period 2002–2013.ResultsTwenty-two studies met the criteria and were included in the systematic review.ConclusionThe analyzed studies demonstrated that after cochlear implant surgery, individuals with auditory neuropathy spectrum disorder improved their performance of hearing skills and had similar performance to that of children with sensorineural hearing loss using cochlear implant.     

Speech perception in cochlear implant users with the HiRes 120 strategy: a systematic review

Despite technological advances employed in signal processing strategies, one of the remaining obstacles are spectral gap details on the information transmitted. Considering its importance in speech perception, researchers have investigated mechanisms to optimize spectral details through virtual spectral channels. The clinical application of this technique resulted in a new approach to signal processing - the HiRes 120.ObjectiveTo assess the auditory performance of cochlear implant users with the HiRes 120 strategy.MethodologyThe literature review was conducted in an electronic database, with standard bibliographic search in the year 2011, using specific keywords. In order to select and evaluate the scientific studies found in the search, we setup search containing the following aspects: type of study, subjects, intervention used and evaluation of the results.ConclusionScientific evidence points to an improvement in hearing performance in noisy environments with the HiRes 120 strategy, but this does not occur in quiet situations. The optimization of speech perception with this strategy is closely related to the cochlear implant user's age, to the time of sensory deprivation and the acclimatization time required to use the strategy's spectral information.     

Evaluation protocol for amusia - portuguese sample

Amusia is a disorder that affects the processing of music. Part of this processing happens in the primary auditory cortex. The study of this condition allows us to evaluate the central auditory pathways.ObjectiveTo explore the diagnostic evaluation tests of amusia.MethodThe authors propose an evaluation protocol for patients with suspected amusia (after brain injury or complaints of poor musical perception), in parallel with the assessment of central auditory processing, already implemented in the department. The Montreal Evaluation of Battery of amusia was the basis for the selection of the tests. From this comprehensive battery of tests we selected some of the musical examples to evaluate different musical aspects, including memory and perception of music, ability concerning musical recognition and discrimination. In terms of memory there is a test for assessing delayed memory, adapted to the Portuguese culture. Prospective study.Results and ConclusionsAlthough still experimental, with the possibility of adjustments in the assessment, we believe that this assessment, combined with the study of central auditory processing, will allow us to understand some central lesions, congenital or acquired hearing perception limitations.     

Hearing aid fitting and unilateral auditory deprivation: behavioral and electrophysiologic assessment

The phenomenon of Late-Onset Unilateral Auditory Deprivation was first reported in 1984. However, a high number of unilateral hearing aid fittings are still carried out in cases of bilateral hearing loss, justified by non-auditory factors such as cost, vanity, misinformation and public health policies.ObjectiveTo carry out behavioral and electrophysiological assessment of the auditory performance of adults using unilateral amplification compared with individuals exposed to bilateral symmetric auditory stimulation.MethodThirty five adults, all with symmetric bilateral sensorineural hearing loss, regular users of unilateral hearing aid, bilateral hearing aids and not users of hearing aids, were assessed on behavioral and electrophysiological tests.ResultsVariance analysis revealed that in the unilaterally fitted group, P300 latency was significantly greater in ears with auditory deprivation compared with those fitted with the hearing aid (p < 0.05). This same group also had poorer performance on the Sentence Recognition Test in Noise held in free field.ConclusionThese results corroborate findings in the literature showing that unilateral auditory deprivation can lead to physiological and perceptual changes.     

Audiological and subjective outcomes of 100 implanted transcutaneous bone conduction devices and preoperative bone conduction hearing aids in patients with bilateral microtia-atresia

Abstract

Background: Bonebridge (BB) and bone conduction hearing aid (BCHA) are effective in patients with bilateral congenital microtia-atresia (CMA).

Objectives: To investigate and compare the outcomes of these devices in a large sample size.

Materials and methods: This single center prospective study involved 100 patients with bilateral CMA who were implanted with BBs and used BCHAs before implantation. Sound field threshold (SFT), speech reception thresholds (SRTs) and word recognition scores (WRSs) were compared between unaided, BCHA used and implanted patients. The Abbreviated Profile of Hearing Aid Benefit (APHAB) was used to evaluate subjective satisfaction.

Results: Compared to unaided condition, the SFT, WRS and SRT of BCHA and BB were significantly improved. With BCHA or BB, the three subscale scores of the APHAB (ease of communication, background noise and reverberation) significantly reduced. However, the aversiveness subscale scored significantly higher than unaided condition. All outcomes were better in BB condition than BCHA.

Conclusions: BB or BCHA use can be considered as effective methods to improve audiological outcomes and subjective satisfaction. Although not as good as BB, BCHA use is critical for improving hearing in the early period of language and auditory pathway development before the skull is suitable for BB implantation.     

The World Health Organization’s hearing-impairment grading system: an evaluation for unaided communication in age-related hearing loss

Objective: This review evaluated the data from five datasets having pure-tone thresholds and functional measures of speech communication from relatively large groups of older adults to evaluate the validity of the proposed new World Health Organisation (WHO) hearing-impairment grading system, referred to here as WHO-proposed.

Design: This was a review of studies identified from the literature having both pure-tone audiometry and functional measures of speech communication from relatively large samples of older adults.

Study sample: Three population or population-sample datasets and two clinical datasets were identified with access provided to de-identified data for five of these six studies.

Results: As the WHO-proposed hearing-impairment grade progressed from “normal” to “severe” (insufficient data from older adults were available for the “profound” category), each step in this progression led to a significant difference in functional communication relative to the preceding step. Cohen’s d effect sizes were moderate to very large between each successive step on the WHO-proposed hearing-impairment grading scale, with some exceptions for the step from “normal” to “mild/slight” grades.

Conclusions: The WHO-proposed hearing-impairment grading system, recently developed through expert opinion and adopted by WHO, is validated here with evidence from studies of functional communication in older adults.     

Implications of musical practice in central auditory processing: a systematic review

IntroductionRecent studies have shown that musical practice and training are effective and have the potential to assist in the acquisition and improvement of auditory skills.ObjectiveTo verify the scientific evidence on the implications of musical practice in central auditory processing.MethodsA systematic review was carried out in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), using the Medline (Pubmed), LILACS, SciELO, BIREME, Scopus and Web of Science databases. The search period for the articles covered the last 5 years (2015–2020), without restriction of language and location. The quality of the articles was assessed, and the review included articles with a minimum score of 6 in a modified literature quality scale.ResultsInitially, 1362 publications were found, of which 1338 were excluded after the title screening, 15 were excluded due to the abstract, with nine articles being analyzed in full and four of them excluded after the analysis, as they did not answer the guiding question proposed for this research. Five articles that met the proposed inclusion criteria were admitted for this research. It was found that in adults, musical ability is associated with better performance of several auditory processing skills, as well as the fact that musical training in children promoted an accelerated maturity of auditory processing and exposure to music facilitated the learning of auditory information in newborns.ConclusionConsidering the scientific evidence, it was found that the musical experience can improve specific skills of the central auditory processing, regardless of age, optimizing children’s linguistic development.     

Contemporary surgical issues in paediatric cochlear implantation

Abstract

Objective: To review the contemporary surgical issues in paediatric cochlear implantation (CI) based on published evidence. Design: Narrative literature review. Results: Surgical challenges in paediatric CI are discussed, with respect to post meningitic labyrinthitis ossificans; cochlear malformation; cochlear implantation in infants; auditory neuropathy and cochlear nerve deficiency; bilateral cochlear implantation; hearing preservation; otitis media; and device failure. Conclusion: Early CI is recommended if bacterial meningitis causes profound sensorineural hearing loss (SNHL). CI in cochleovestibular malformation requires pre-operative imaging to plan surgical technique, choice of electrode, and to anticipate complication. Children with congenital severe to profound SNHL should undergo early bilateral simultaneous implantation, preferably before 12 months of age, except those with auditory neuropathy spectrum disorder who should be implanted after one year. Soft surgical technique should be deployed in an attempt to preserve any residual hearing. Otitis media with effusion is not a contraindication to cochlear implantation, but active or recurrent acute otitis media requires resolution of infection with grommet insertion pre-operatively. Device failure in CI recipients requires a stepwise audiological, medical, radiological, and device integrity assessment to determine the need for reimplantation.     

Identifying emotions in music through electrical hearing in deaf children using cochlear implants

Abstract

Objective: Cochlear implant (CI) devices are the choice of treatment for individuals with severe to profound hearing loss. The CI devices provide the opportunity for children who are deaf to perceive sound by electrical stimulation of the auditory nerve, with the goal of optimizing oral communication. A natural benefit of acquiring hearing using CIs is the ability to hear, and perhaps enjoy, music. Music is a non-verbal auditory stimulus and a powerful tool for transmitting emotion. Identifying emotional cues is an important part of normal social development and communication and thus music may play an important role in establishing these skills during development. To date, it is not known whether children who use cochlear implants to hear can identify the emotional content carried in music. Our objective in the present study was to determine whether children who have been deaf from infancy and are experienced CI users have acquired the ability to identify emotion in musical phrases.

Method: Study participants were 18 CI users (ages 7–13 years) who received right unilateral CIs (mean age at CI activation of 2.9 years) and 18 age-and gender-matched controls. Participants were asked to judge 32 brief musical excerpts as happy or sad by pointing to simple graphics of a smiling or frowning face.

Results: Children using CIs were able to correctly distinguish happy versus sad music well above chance levels, but performed more poorly on this task than their peers with typical hearing. Age at CI activation and time since CI activation were both uncorrelated with outcome measures.

Conclusion: Children with CIs show the ability to perceive emotion in music but do so less accurately than typically hearing peers.     

A systematic review of electrophysiological outcomes following auditory training in school-age children with auditory processing deficits

Abstract

Objective: To systematically review the peer-reviewed literature on electrophysiological outcomes following auditory training (AT) in school-age children with (central) auditory processing disorder ([C]APD). Design: A systematic review. Study sample: Searches of 16 electronic databases yielded four studies involving school-aged children whose auditory processing deficits had been confirmed in a manner consistent with and and compared to a treated and/or an untreated control group before and after AT. A further three studies were identified with one lacking a control group and two measuring auditory processing in a manner not consistent with and . Results: There is limited evidence that AT leads to measurable electrophysiological changes in children with auditory processing deficits. Conclusion: The evidence base is too small and weak to provide clear guidance on the use of electrophysiological outcomes as a measure of AT outcomes in children with auditory processing problems. The currently limited data can only be used to suggest that click-evoked AMLR and tone-burst evoked auditory P300 might be more likely to detect such outcomes in children diagnosed with (C)APD, and that speech-evoked ALLR might be more likely to detect phonological processing changes in children without a specific diagnosis of (C)APD.     

Auditory processing performance in blind people

Hearing has an important role in human development and social adaptation in blind people.ObjectiveTo evaluate the performance of temporal auditory processing in blind people; to characterize the temporal resolution ability; to characterize the temporal ordinance ability and to compare the performance of the study population in the applied tests.MethodsFifteen blind adults participated in this study. A cross-sectional study was undertaken; approval was obtained from the Pernambuco Catholic University Ethics Committee, no. 003/2008.ResultsTemporal auditory processing was excellent - the average composed threshold in the original RGDT version was 4.98 ms; it was 50 ms for all frequencies in the expanded version. PPS and DPS results ranged from 95% to 100%. There were no quantitative differences in the comparison of tests; but oral reports suggested that the original RGDT original version was more difficult.ConclusionThe study sample performed well in temporal auditory processing; it also performed well in temporal resolution and ordinance abilities.     

Newborn hearing screening in the limiar clinic in Porto Velho Rondônia

With the universal hearing screening we can prevent auditory disorders in children.AimTo characterize the program of neonatal auditory screening into a population of neonates.Materials and Methodslongitudinal cohort study. We surveyed the clinic's database on neonatal auditory screening in the city of Porto Velho, Rondônia.ResultsAmong the 6,889 newborns in the database, 5,700 (82.7%) passed and 1,189 (17.3%) failed the first screening. Of the group which failed 900 (75.7 %) returned for retesting. Among these, 15 (0.22 %) newborns had hearing loss confirmed. The most prevalent was neural hearing loss with 46.7% confirmed cases; they had hyperbilirubinemia as the most prevalent risk factor.Conclusionhyperbilirubinemia was the most prevalent risk factor found in the group of hearing impaired children. The prevalence of hearing loss was of 2 in 1,000 newborns. It is important to highlight the relevant association between neural hearing loss caused by hyperbilirubinemia and sensorineural hearing loss of unknown causes.     

Association between top-down skills and auditory processing tests

Today, we are questioning how top-down skills may interfere with performance on auditory processing tests.ObjectiveTo investigate the existence of a possible association between memory, attention and language skills in auditory processing tests in “normal” development children.MethodTwenty children (ages 7 to 9 years), without complaints related to verbal and/or written language skills; without overt neurological or psychological involvement or delayed psychomotor development. We employed Hearing and auditory Processing Assessment tests in addition to psychophysical tests (visual and auditory attention tests; memory tests for digits and syllables and phonological awareness tests).Resultsthere was a “very strong” correlation between Frequency Pattern and Memory for Digits Tests; a “strong” correlations between SSW (LE) test and Memory for Syllables, and SSW (LE) test and phonemic tasks.Conclusionthe Frequency Pattern Test showed a strong correlation with the phonological working memory skill; just as the SSW had with language and memory skills for syllables. It is noteworthy the difficult to clinically interpret the results of each auditory processing test alone, since these may be dependent on skills not necessarily related to the auditory modality, such as memory and language.     

An auditory health program for neonates in ICU and/or intermediate care settings

Auditory screening and early identification and management of patients with hearing loss improve the development prospects of infants.ObjectiveTo analyze the outcomes produced by an Auditory Health Program in neonates managed in an intensive care unit.MethodThis prospective cross-sectional study enrolled neonates referred to the neonatal care unit at hospital CAISM/Unicamp with stays lasting for 48 hours and more within a period of 13 months.Automated monitoring of brainstem auditory evoked potentials was used in the auditory screening of neonates at the time of discharge. Children with poor BAEPs were sent to undergo audiological, otorhinolaryngological, and genetic tests.ResultsAuditory screening was performed for 84.7% of the live births; 39.7% were screened at 30 days or more of age. Diagnostic tests revealed that 63.8% of the children had normal hearing. Incidence of hearing loss was 4%; sensorineural hearing loss was observed in 1.4% of the subjects; 0.24% had auditory neuropathy spectrum disorder; and 2.2% had conductive hearing loss.ConclusionNeonatal auditory screening was not offered universally, and nor was it carried out, in many cases, within the child's first month of life. Screening must be performed before neonates are discharged and in more than one stage. A high incidence of hearing loss was observed.