Prevalence of presbycusis in an otologically normal population / Prevalencia de presbiacusia en una población otológicamente norma

OBJECTIVE: Presbycusis or age-related hearing loss is a bilaterally symmetric sensorineural hearing loss associated exclusively with age, excluding any other causes of hearing loss. Presbycusis is very relevant because of its high prevalence, and its consequences (e.g., alterations in communication, social isolation, depression, dementia), and the economic impact. This paper reports the first attempt to estimate the prevalence of presbycusis in an otologically normal population, i.e., without previous ear disease, exposure to noise, or potentially ototoxic substances, or familial hearing loss. METHODS: A total of 4290 subjects from 5 to 90 years old were included in the study. RESULTS: No statistically significant differences were found between right and left ear, nor between males and females, in any of the age groups. Presbycusis was detected over 60 years following the WHO classification; although the results vary depending on the classification used. Moderate hearing loss (≥ 41 dB) was detected in the population over 72 years. None of the subjects had severe or profound hearing impairment. The prevalence of presbycusis increased with age, being 100% in individuals aged 80 years and older. The prevalence of presbycusis is highly variable depending on the pure-tone averaged frequencies and the classification system used; therefore, a common classification system should be used. CONCLUSIONS: An otologically normal population is needed to establish the prevalence of presbycusis as in non-screened populations it is the hearing level including all types of hearing loss that is measured, but not presbycusis itself

ANTECEDENTES Y OBJETIVO: La presbiacusia o pérdida auditiva relacionada con la edad, es una hipoacusia neurosensorial bilateral y simétrica asociada exclusivamente a la edad. La presbiacusia es muy relevante debido a su alta prevalencia y sus consecuencias (alteraciones en la comunicación, aislamiento social, depresión, demencia) y el impacto económico. Este es el primer trabajo que aporta datos sobre la prevalencia de la presbiacusia en una población otológicamente normal, es decir, sin enfermedad auditiva previa, exposición a ruido o sustancias potencialmente ototóxicas o pérdida de audición familiar. MATERIAL Y MÉTODOS: Un total de 4.290 sujetos de 5 a 90 años de edad fueron incluidos en el estudio. RESULTADOS: No se encontraron diferencias entre el oído derecho y el izquierdo, ni entre varones y mujeres. La presbiacusia se detectó a partir de los 60 años siguiendo la clasificación de la OMS, aunque los resultados varían dependiendo de la clasificación utilizada. Se detectó hipoacusia moderada (≥ 41dB) en la población mayor de 72 años. Ninguno de los sujetos tenía hipoacusia grave o profunda. La prevalencia de presbiacusia aumentó con la edad, siendo del 100% en individuos de 80 años o más. La prevalencia de la presbiacusia es altamente variable dependiendo de las frecuencias promediadas y del sistema de clasificación utilizado; por lo tanto, debería utilizarse un sistema de clasificación común. CONCLUSIONES: Para establecer la prevalencia de la presbiacusia se necesita una población otológicamente normal ya que, si la población no está cribada, lo que se mide es la hipoacusia que incluye todos los tipos de pérdida auditiva, pero no la presbiacusia de forma aislada

A Novel Method for Classifying Hearing Impairment in Epidemiological Studies of Aging: The Wisconsin Age-Related Hearing Impairment Classification Scale.

Purpose Longitudinal population-based cohort data were used to develop a standardized classification system for age-related hearing impairment using thresholds for frequencies (0.5-8 kHz) typically measured in cohort studies. Method Audiometric testing data collected in the Epidemiology of Hearing Loss Study from participants (n = 1,369) with four visits (1993-1995, 1998-2000, 2003-2005, and 2009-2010) were included (10,952 audiograms). Cluster analyses (Wald's method) were used to identify audiometric patterns. Maximum allowable threshold values were defined for each cluster to create an ordered scale. Progression was defined as a two-step change. Results An eight-step scale was developed to capture audiogram shape and severity of hearing impairment. Of the 1,094 participants classified as having normal hearing based on a pure-tone average, only 25% (n = 277) were classified as Level 1 (all thresholds ≤ 20 dB HL) on the new scale, whereas 17% (n = 182) were Levels 4-6. During the 16-year follow-up, 64.9% of those at Level 1 progressed. There was little regression using this scale. Conclusions This is the first scale developed from population-based longitudinal cohort data to capture audiogram shape across time. This simple, standardized scale is easy to apply, reduces misclassification of normal hearing, and may be a useful method for identifying risk factors for early, preclinical, age-related changes in hearing.

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.

Etiological classification of presbycusis in Turkish population according to audiogram configuration.

OBJECTIVES: This study aims to classify age related hearing loss in Turkish population according to Schuknecht audiometric configurations for presbycusis and investigate the most common etiologies. PATIENTS AND METHODS: A total of 1,134 patients (568 males, 566 females; mean age 70.5±7.7 years; range 55 to 80 years) with age related hearing loss were included in the study. Audiograms of patients were classified into three categories: high frequency steeply sloping (HFSS), flat, and high frequency gently sloping (HFGS). Speech discrimination scores were evaluated and compared. RESULTS: In the study population, HFSS audiogram configuration was the most frequently observed (48.5%), followed by HFGS configuration (26.9%), and flat configuration (24.5%), respectively. While HFSS audiogram configuration was statistically significantly more common in males, flat audiogram configuration was statistically significantly more common in females (p=0.0001). HFSS group mean air conduction threshold were statistically significantly higher than flat and HFGS groups (p=0.0001). No statistically significantly difference was detected in terms of speech discrimination scores between three groups (p=0.796). CONCLUSION: Results of this study suggest that, in Turkish population, while sensory presbycusis is more common in males, strial presbycusis is more common in females. No difference was detected in terms of the prevalence of cochlear presbycusis in males and females (p=0.0001).

Classifying human audiometric phenotypes of age-related hearing loss from animal models.

Age-related hearing loss (presbyacusis) has a complex etiology. Results from animal models detailing the effects of specific cochlear injuries on audiometric profiles may be used to understand the mechanisms underlying hearing loss in older humans and predict cochlear pathologies associated with certain audiometric configurations ("audiometric phenotypes"). Patterns of hearing loss associated with cochlear pathology in animal models were used to define schematic boundaries of human audiograms. Pathologies included evidence for metabolic, sensory, and a mixed metabolic + sensory phenotype; an older normal phenotype without threshold elevation was also defined. Audiograms from a large sample of older adults were then searched by a human expert for "exemplars" (best examples) of these phenotypes, without knowledge of the human subject demographic information. Mean thresholds and slopes of higher frequency thresholds of the audiograms assigned to the four phenotypes were consistent with the predefined schematic boundaries and differed significantly from each other. Significant differences in age, gender, and noise exposure history provided external validity for the four phenotypes. Three supervised machine learning classifiers were then used to assess reliability of the exemplar training set to estimate the probability that newly obtained audiograms exhibited one of the four phenotypes. These procedures classified the exemplars with a high degree of accuracy; classifications of the remaining cases were consistent with the exemplars with respect to average thresholds and demographic information. These results suggest that animal models of age-related hearing loss can be used to predict human cochlear pathology by classifying audiograms into phenotypic classifications that reflect probable etiologies for hearing loss in older humans.

Central presbycusis: a review and evaluation of the evidence.

BACKGROUND: The authors reviewed the evidence regarding the existence of age-related declines in central auditory processes and the consequences of any such declines for everyday communication. PURPOSE: This report summarizes the review process and presents its findings. DATA COLLECTION AND ANALYSIS: The authors reviewed 165 articles germane to central presbycusis. Of the 165 articles, 132 articles with a focus on human behavioral measures for either speech or nonspeech stimuli were selected for further analysis. RESULTS: For 76 smaller-scale studies of speech understanding in older adults reviewed, the following findings emerged: (1) the three most commonly studied behavioral measures were speech in competition, temporally distorted speech, and binaural speech perception (especially dichotic listening); (2) for speech in competition and temporally degraded speech, hearing loss proved to have a significant negative effect on performance in most of the laboratory studies; (3) significant negative effects of age, unconfounded by hearing loss, were observed in most of the studies of speech in competing speech, time-compressed speech, and binaural speech perception; and (4) the influence of cognitive processing on speech understanding has been examined much less frequently, but when included, significant positive associations with speech understanding were observed. For 36 smaller-scale studies of the perception of nonspeech stimuli by older adults reviewed, the following findings emerged: (1) the three most frequently studied behavioral measures were gap detection, temporal discrimination, and temporal-order discrimination or identification; (2) hearing loss was seldom a significant factor; and (3) negative effects of age were almost always observed. For 18 studies reviewed that made use of test batteries and medium-to-large sample sizes, the following findings emerged: (1) all studies included speech-based measures of auditory processing; (2) 4 of the 18 studies included nonspeech stimuli; (3) for the speech-based measures, monaural speech in a competing-speech background, dichotic speech, and monaural time-compressed speech were investigated most frequently; (4) the most frequently used tests were the Synthetic Sentence Identification (SSI) test with Ipsilateral Competing Message (ICM), the Dichotic Sentence Identification (DSI) test, and time-compressed speech; (5) many of these studies using speech-based measures reported significant effects of age, but most of these studies were confounded by declines in hearing, cognition, or both; (6) for nonspeech auditory-processing measures, the focus was on measures of temporal processing in all four studies; (7) effects of cognition on nonspeech measures of auditory processing have been studied less frequently, with mixed results, whereas the effects of hearing loss on performance were minimal due to judicious selection of stimuli; and (8) there is a paucity of observational studies using test batteries and longitudinal designs. CONCLUSIONS: Based on this review of the scientific literature, there is insufficient evidence to confirm the existence of central presbycusis as an isolated entity. On the other hand, recent evidence has been accumulating in support of the existence of central presbycusis as a multifactorial condition that involves age- and/or disease-related changes in the auditory system and in the brain. Moreover, there is a clear need for additional research in this area.

Presbycusis phenotypes form a heterogeneous continuum when ordered by degree and configuration of hearing loss.

Many reports have documented age-by-frequency increases in average auditory thresholds in various human populations. Despite this, the prevalence of different patterns of hearing loss in presbycusis remains uncertain. We examined 'presbycusis phenotypes' in a database of 960 subjects (552 female, 408 male, 18-92 years) that each had 30 measures of peripheral hearing sensitivity: pure tone audiograms for left and right ears from 0.25 to 8 kHz and DPOAE for each ear with F(mean)=1-6.4 kHz. Surprisingly, the hearing phenotypes did not naturally separate into discrete classes of presbycusis. Principal component (PC) analysis revealed that two principal components account for 74% of the variance among the 30 measures of hearing. The two components represent the overall degree (PC1) and configuration of loss (Flat vs. Sloping; PC2) and the phenotypes form a continuum when plotted against them. A heuristic partitioning of this continuum produced classes of presbycusis that vary in their degree of Sloping or Flat hearing loss, suggesting that the previously reported sub-types of presbycusis arise from the categorical segregation of a continuous and heterogeneous distribution. Further, most phenotypes lie intermediate to the extremes of either Flat or Sloping loss, indicating that if audiometric configuration does predict presbycusis etiology, then a mixed origin is the most prevalent.

Older adults with acquired hearing impairment: applying the ICF in rehabilitation.

The aim of this article is to describe the disability experienced by older people with hearing impairment using the framework provided by the World Health Organization's International Classification of Functioning, Disability and Health (ICF). The nature and prevalence of hearing impairment in the older population are outlined, along with the Activity Limitations and Participation Restrictions associated with such impairments, and the contextual factors that influence the disability. Appropriate assessments of hearing Impairments, Activity Limitations, and Participation Restrictions applicable in a rehabilitation context are also described. Hearing impairment leads to breakdowns in communication, a fact that suggests that the impairment is likely to influence frequent communication partners. It is argued here that the impact of the impairment on others is a so-called Third-Party Disability. Finally, an example of how the ICF can be applied in the rehabilitation of an older person with hearing disability is presented.

[Hearing aids in the elderly. Why is the accommodation so difficult?]. / Hörgeräte im Alter. Warum ist die Versorgung so schwierig?

UNLABELLED: PRELIMINARY REMARKS: The acceptance of hearing-aids by elderly people is generally poor. Hearing loss on the other hand increases with age, and the ability to communicate,especially in random noise, diminishes. PATIENTS AND METHODS: Audiometric data on 331 individuals older than 60 years were collected. Sixty people between 15 and 30 and 86 people between 31 and 60 years acted as controls. Tympanograms, hearing thresholds, speech audiometry and dichotic hearing as well as binaural masking level differences and otoacustic emissions for eight frequencies were measured. Hearing aid status was also determined. RESULTS: Our data show more hearing deficits at low frequencies as indicated in the literature. Presbycusis is present solely in the internal ear in 11.5-27.7%, in central hearing structures in 3.8-21.4%, but mainly in all parts of the auditory pathway 50.9-84.6% of cases. Only 15.3% of patients needing hearing aids were actually provided with them. CONCLUSION: Hearing decreases with age but some older people have completely normal hearing. Therefore, a physiological presbycusis does not exist. There are deficits in the inner ear as well as in the central auditory structures which should be determined by audiometric diagnosis. Hearing aid supply should be carefully regulated and audiotherapy carried out.

[Hearing handicap--an addition to audiometric hearing loss. Results of an exploratory study of auditory communication disorders in the elderly]. / Das Hörhandicap--Eine Ergänzung zum audiometrischen Hörverlust. Ergebnisse einer explorativen Studie über auditive Kommunikationsstörungen im Alter.

Hearing problems in elderly patients cannot be evaluated completely with conventional audiological tests in most cases. Two hundred and one subjects aged 60 years or more complaining of hearing problems were studied. The following tests were employed: pure-tone audiometry, the "Basler Satztest" (a German version of the SPIN-test assessing speech perception in noise), and a German version of a "Hearing Handicap Inventory for the Elderly" (HHIE). These latter versions were developed in our institution. An auditory handicap was found in one-third of subjects with mild hearing losses (PTA < 30 dB; n = 135) and in two-thirds of subjects with greater hearing losses (PTA > and = 30 dB; n = 65). The relatively weak correlations of the pure-tone audiogram (r = 0.49) or speech audiometry (r = 0.41) with HHIE indicate that more than 50% of the variance of the hearing handicap was due to non-audiologic factors. For this reason, we recommend that the handicap questionnaire be added to the audiometric evaluation.

Presbiacusia / Presbicusis

Através desta revisäo bibliográfica, os autores visam abordar a presbiacusia, tomando em consideraçäo aspectos etiológicos, diagnósticos e de conduta

Cochlear pathology in presbycusis.

A survey of the temporal bone collection at the Massachusetts Eye and Ear Infirmary reveals 21 cases that meet the criterion for the clinical diagnosis of presbycusis. It is evident that the previously advanced concept of four predominant pathologic types of presbycusis is valid, these being sensory, neural, strial, and cochlear conductive. An abrupt high-tone loss signals sensory presbycusis, a flat threshold pattern is indicative of strial presbycusis, and loss of word discrimination is characteristic of neural presbycusis. When the increments of threshold loss present a gradually decreasing linear distribution pattern on the audiometric scale and have no pathologic correlate, it is speculated that the hearing loss is caused by alterations in the physical characteristics of the cochlear duct, and the loss is identified as cochlear conductive presbycusis. It is clear that many individual cases do not separate into a specific type but have mixtures of these pathologic types and are termed mixed presbycusis. About 25% of all cases of presbycusis show none of the above characteristics and are classified as indeterminate presbycusis.

Morphological correlates of aging in the chinchilla cochlea.

The inner ears from 80 chinchillas ranging in age from premature to 19.2 years were examined as plastic-embedded flat preparations to determine the morphological changes associated with aging. Three of the four forms of human presbycusis defined by Schuknecht were found in the chinchillas. All animals had losses of sensory cells or sensory presbycusis. Inner (IHCs) and outer hair cells (OHCs) degenerated at a rate of about 0.29% and 1.0% per year, respectively. Age-related degeneration of inner (IPs) and outer pillars (OPs) occurred at a much slower rate. In four animals (5%) the dendritic processes of some of the spiral ganglion cells had degenerated in areas where the loss of sensory cells was minimal. This pathological change is likely equivalent to neural presbycusis. Six animals (7.5%) had regions of degeneration of the stria vascularis or strial presbycusis. The other common finding in the aging cochleas was the presence of lipofuscin or age pigment. Lipofuscin deposits were found to accumulate in the subcuticular region of OHCs, IPs and OPs, near the endolymphatic surfaces of many of the supporting cells and in the epithelial cells of Reissner's membrane. The IHCs accumulated much less lipofuscin. The morphological changes seen in the ears of aging chinchillas were qualitatively similar to those seen in the temporal bones of aging humans although the magnitude of the changes was considerably less. These results suggest that some of the damage found in aging human cochleas may be due to aging plus exposure to one or more ototraumatic agents.

Restoring hearing to the older patient: the physician's role.

There is growing evidence that failure to diagnose and manage hearing problems early in their course results in significant and--to some extent--irreversible sensory deprivation. The primary care physician should routinely screen patients over age 50 for pure-tone sensitivity as part of the general physical examination. Battery-operated, in-office, limited-frequency audiometers are available for under $350.

Differentiation of types of presbycusis using the masking-level difference.

Masking-level differences in quiet at 500 Hz were used to demonstrate evidence of elevated noise levels within the auditory systems of subjects with assumed neural presbycusis. The following five groups of subjects were evaluated: normal-hearing young and old adults; and older adults with metabolic, sensory, or neural presbycusis. The group with assumed neural presbycusis--that is, bilateral high-frequency sensorineural hearing loss and poor word-recognition performance--had masking-level differences (a) in quiet that were significantly larger than those for the other groups and (b) in noise that were significantly smaller than those for the other groups. The data suggest that elevated internal noise levels accompany neural presbycusis.

Presbycusis: the need for a clinical definition.

The term presbycusis is vague and needs specific signs and symptoms for its definition. Several types of presbycusis, depending on the type of lesion, have been proposed. This article suggests a working definition of "classic presbycusis," which may be defined as a syndrome involving (1) a bilaterally symmetric sensorineural hearing loss, (2) absent or partial recruitment, (3) negative noise history, and (4) poorer speech discrimination than indicated by pure tones (phonemic regression).

Presbycusis: what is it?

The history and current misusage of the term presbycusis is discussed and current knowledge of pathology associated with presbycusis and aging are reviewed. A study involving retrospective analysis of audiometric data and clinical information on three groups was performed. Results suggest that a group of individuals previously identified as "presbycusic" probably represent undiagnosed cases of familial or genetic related hearing loss. We urge as thorough an identification of correct diagnosis as possible, thus reserving the term "presbycusis" for those rare, soley age-related cases of sensorineural loss.