Hearing acuity in nonagenarians aged 90 and 95 assessed in a home setting using standardized pure-tone audiometry.

OBJECTIVE: Knowledge regarding hearing acuity in the nonagenarian age group is sparse. In this study we aimed to advance our understanding of hearing loss in the 10th decade of life. DESIGN: A cross-sectional study in which standardised hearing measurements were performed during home visits, which included care home facilities and nursing homes to maximise participation. STUDY SAMPLE: Two unselected groups of individuals aged 90 (n = 42) and 95 (n = 49), sampled from the population-based Gothenburg H70 Birth Cohort Studies. RESULTS: 98% of the participants (95% CI [95, 100]) had some degree of hearing loss in their better ear, with 83% (95% CI [73, 89]) having a potentially disabling hearing loss of moderate degree or worse, according to WHO criteria. Furthermore, differences between the two age groups (five years apart) indicate an increasing hearing loss, primarily at frequencies ≥ 2 kHz. CONCLUSION: Hearing loss was present in almost all of the participants in the nonagenarian age group and among a majority of them potentially to a degree that would warrant rehabilitation. Carrying out standardised hearing measurements in a home setting was feasible in this age group and enhanced the representativeness of the study population.

Bilateral hearing loss affected almost all of the individuals in the nonagenarian age group with 8 in 10 having hearing loss of a degree severe enough to warrant intervention or hearing aid prescription.The findings provide valuable insight into hearing acuity among nonagenarians. Many earlier studies were limited to subjective hearing assessments, reviews of medical records and/or screening tests performed by non-audiologists.The final sample size was smaller than initially planned due to the COVID-19 pandemic. However, measures were taken to optimise the representativeness of the study sample.

Hearing Loss and Cognitive Function in Early Old Age: Comparing Subjective and Objective Hearing Measures.

INTRODUCTION: Population-based research has consistently shown that people with hearing loss are at greater risk of cognitive impairment. We aimed to explore the cross-sectional association of both subjective and objective hearing measures with global and domain-specific cognitive function. We also examined the influence of hearing aid use on the relationship. METHODS: A population-based sample (n = 1,105, 52% women) of 70-year-olds that were representative of the inhabitants of the city of Gothenburg, Sweden completed a detailed cognitive examination, pure-tone audiometry, and a questionnaire regarding perceived hearing problems. A subsample (n = 247, 52% women) also completed a test of speech-recognition-in-noise (SPRIN). Multiple linear regression analyses were conducted to explore the association of hearing with cognitive function, adjusting for sex, education, cardiovascular factors, and tinnitus. RESULTS: Global cognitive function was independently associated with the better ear pure-tone average across 0.5-4 kHz (PTA4, ß = -0.13, 95% CI, -0.18, -0.07), the better ear SPRIN score (ß = 0.30, 95% CI, 0.19, 0.40), but not with the self-reported hearing measure (ß = -0.02, 95% CI, -0.07, 0.03). Both verbally loaded and nonverbally loaded tasks, testing a variety of cognitive domains, contributed to the association. Hearing aid users had better global cognitive function than nonusers with equivalent hearing ability. The difference was only significant in the mild hearing loss category. DISCUSSION: In a population-based sample of 70-year-old persons without dementia, poorer hearing was associated with poorer global and domain-specific cognitive function, but only when hearing function was measured objectively and not when self-reported. The speech-in-noise measure showed the strongest association. This highlights the importance of including standardized hearing tests and controlling for hearing status in epidemiological geriatric research. More research is needed on the role that hearing aid use plays in relation to age-related cognitive declines.

Accuracy of automated pure-tone audiometry in population-based samples of older adults.

OBJECTIVE: Automated pure-tone audiometry is frequently used in teleaudiology and hearing screening. Given the high prevalence of age-related hearing loss, older adults are an important target population. This study aimed to investigate the accuracy of automated audiometry in older adults, and to examine the influence of test frequency, age, sex, hearing and cognitive status. DESIGN AND STUDY SAMPLE: In a population-based study, two age-homogeneous samples of 70-year-olds (n = 238) and 85-year-olds (n = 114) were tested with automated audiometry in an office using circum-aural headphones and, around 4 weeks later, with manual audiometry conducted to clinical standards. The differences were analysed for individual frequencies (range: 0.25-8 kHz) and pure-tone averages. RESULTS: The mean difference varied across test frequencies and age groups, the overall figure being -0.7 dB (SD = 8.8, p < 0.001), and 68% to 94% of automated thresholds corresponded within ±10 dB of manual thresholds. The poorest accuracy was found at 8 kHz. Age, sex, hearing and cognitive status were not associated with the accuracy (ordinal regression analysis). CONCLUSIONS: Automated audiometry seems to produce accurate assessments of hearing sensitivity in the majority of older adults, but with larger error margins than in younger populations, and is not affected by relevant patient factors associated with old age.

Prevalence of hearing loss and need for aural rehabilitation in 85-year-olds: a birth cohort comparison, almost three decades apart.

OBJECTIVE: Many individuals >80 years have difficulties with speech communication due to age-related hearing loss and would benefit from aural rehabilitation. As the proportion of older people increases, there is a need to investigate the prevalence of "disabling hearing loss" to calculate future rehabilitation need. The aims are to determine the prevalence of hearing loss in an unscreened birth cohort of 85-year olds, and to identify differences in audiometric results between two birth cohorts, born 28-29 years apart. DESIGN: This is a population-based, cross-sectional study that is part of the Gothenburg H70 Birth Cohort Studies. STUDY SAMPLE: Hearing thresholds were measured and compared between 85-year olds born in 1930 (n = 286) and 1901-1902 (n = 249). RESULTS: Based on the WHO criteria, the prevalence of "disabling hearing loss" was 45% for men and 43% for women in the latest birth cohort. Hearing thresholds (0.5-4 kHz) for men improved compared with the earlier birth cohort. No such difference was observed for women. CONCLUSION: The prevalence of age-related hearing loss over three decades has decreased among 85-year-old men, but has been retained in women. The improvement for men occurred predominantly in the low-mid frequencies. An increased need for aural rehabilitation is expected due to demographic changes.

Prognostic Value of a Test of Central Auditory Function in Conversion from Mild Cognitive Impairment to Dementia.

BACKGROUND/OBJECTIVE: It has been suggested that central auditory processing dysfunction might precede the development of cognitive decline and Alzheimer's disease (AD). The Dichotic Digits Test (DDT) has been proposed as a test of central auditory function. Our objective was to evaluate the predictive capacity of the DDT in conversion from mild cognitive impairment (MCI) to dementia. METHODS: A total of 57 participants (26 females) with MCI were tested at baseline with pure tone audiometry, speech in quiet and in noise, and the DDT. The cognitive outcome was retrieved from medical files after 5 years. Groupwise comparisons of the baseline DDT scores were performed and the relative risk was calculated. RESULTS: Altogether 22 subjects developed any kind of dementia. Of the original 57 individuals within the MCI group, 15 developed AD and 7 developed other types of dementia. There was no significant difference in baseline DDT scores between the participants who converted to AD and those who did not. However, the group who developed other types of dementia (especially frontotemporal dementia) had lower DDT scores in the left ear than those participants who did not develop dementia. With a baseline DDT score below 50% correct responses, the participants diagnosed with MCI had a 2.49-times-higher risk of developing dementia than those with scores of 50% or better. CONCLUSION: The DDT as a central auditory test may be suitable when evaluating cognitive decline.

Prevalence of childhood hearing impairment in the County of Stockholm - a 40-year perspective from Sweden and other high-income countries.

OBJECTIVE: The purpose of this study was to determine the current prevalence of childhood hearing impairment (HI) in Sweden and to compare our data with previous studies from Sweden and other high-income countries. DESIGN: This was a cross-sectional study based on a register of children diagnosed with HI. Our results were compared with prevalence data from 18 studies from Sweden and other high-income countries, covering data collected from 1964 to the present. STUDY SAMPLE: In December 2017, a total of 1911 out of 524,957 children 0-18 years of age and living in Stockholm County were enrolled in the regional programme for HI intervention. RESULTS: The overall prevalence of unilateral and bilateral HI >20 dB was 3.6/1000. The overall prevalence of bilateral HI >40 dB HL was 1.5/1000, split into age groups the prevalence was 0.4/1000 (<1 year of age), 1/1000 (1-4 years), 1.5/1000 (5-9 years), 1.6/1000 (10-14 years), and 2.14/1000 (15-18 years). From 1 to 18 years of age, the prevalence increased by a factor of 3.5 for moderate to profound HI >40 dB HL (0.7 to 2.4/1000). CONCLUSION: The prevalence of HI across childhood in Stockholm County today is not significantly different from previous reports from Sweden and other high-income countries.

Auditory function and prevalence of specific ear and hearing related pathologies in the general population at age 70.

Objective: To describe the auditory function in early old age in detail based on both psychoacoustic and physiological measures, and to investigate the prevalence of specific audiological and otological pathologies.Design: An unscreened subsample from a population-based geriatric investigation was examined with otoscopy; tympanometry; pure-tone audiometry; word-recognition-in-noise test; distortion-product otoacoustic emissions; and auditory-evoked brainstem responses. Audiometric subtypes and diagnoses were established based on set criteria. The association between word scores and ABR was examined with linear regression analysis.Study Sample: 251 persons aged 70 (113 men, 138 women, born in 1944) that were representative of the inhabitants of the city of Gothenburg.Results: The prevalence of conductive pathology was 2% versus 49% for cochlear and 2% for auditory-neural pathology. Four percent had indeterminate type. Cochlear dysfunction was present in the majority of ears and around 20% performed worse-than-expected on speech testing. Poor performance on the speech in noise test was associated with prolonged interpeak latency interval of ABR waves I-V.Conclusion: Specific otological and audiological pathologies, other than cochlear hearing loss, are rare in the general population at age 70. Additionally, there is subtle evidence of age-related decline of the auditory nerve. Longitudinal follow-up would be of great interest.

Treatment of military acoustic accidents with N-Acetyl-L-cysteine (NAC).

OBJECTIVE: To study if the antioxidant (AO) N-Acetyl-L-cysteine (NAC) reduces the risk of hearing loss after acoustic accidents in humans. DESIGN: A retrospective, observational study. STUDY SAMPLE: Personnel of the Swedish Armed Forces (SAF) exposed to military acoustic accidents during a 5 year period. Included in the study were 221 cases (mean age: 22.9 years). Most of the exposures, 84%, were weapon related. NAC (400 mg) was given directly after the accident in 146 cases; 75 had not received NAC. RESULTS: The prevalence of hearing thresholds ≥25 dB HL, and the incidence of threshold shifts ≥10 dB, was lower in the NAC group than in the non-NAC group directly after the noise exposure. The deterioration was temporary and not discernable a long time after the accident. The difference was most pronounced in the right ear. The risk reduction to get a temporary hearing loss (TTS), affecting one or both ears was 39% (significant) in the NAC group. CONCLUSIONS: The study has demonstrated a significant reduction of the incidence of TTS by the use of NAC. Since cases of both permanent hearing loss (PTS) and noise-induced tinnitus are recruited from cases with TTS, the demonstrated risk reduction indicates a positive effect of NAC.

Improved hearing in Swedish 70-year olds-a cohort comparison over more than four decades (1971-2014).

Objective: the world population is ageing rapidly. In light of these demographic changes, it is of interest to generate current data regarding the prevalence and characteristics of age-related hearing loss. The purpose of this study was to investigate hearing acuity and the prevalence of hearing loss in a contemporary age-homogenous cohort of old adults, and to assess secular trends in hearing function during the last half-century (1971-2014). Methods: we performed a prospective population-based cohort comparison study of unscreened populations. As part of a geriatric population-based study (H70), a new cohort of 70-year olds (n = 1,135) born in 1944 was tested with computerised automated pure-tone audiometry. The hearing thresholds were compared to three earlier born cohorts of 70-year olds, born in 1901-02 (n = 376), 1906-07 (n = 297) and 1922 (n = 226), respectively. Results: significant improvements in median pure-tone thresholds were seen at several frequencies in both men (range: 5-20 dB, P < 0.01) and women (range: 5-10 dB, P < 0.01). When investigating the effect of birth cohort on hearing in a linear regression, significant trends were found. Men's hearing improved more than women's. The prevalence of hearing loss declined in the study period (1971-2014) from 53 to 28% for men and 37 to 23% for women (P < 0.01). Conclusions: these results indicate that the hearing acuity in Swedish 70-year olds has improved significantly over more than four decades. The largest improvements were seen at 4-6 kHz in men, possibly reflecting a decrease in occupational noise exposure. Further studies are required to pinpoint the reasons for improved hearing-health among older people.

A demonstrated positive effect of a hearing conservation program in the Swedish armed forces.

OBJECTIVE: A revised hearing conservation program (HCP) was implemented in the Swedish Armed Forces in 2002. The aim of this study was to evaluate the incidence of significant threshold shifts (STS) in male conscripts heavily exposed to noise after the implementation of the new HCP, comparing the results to those of an earlier study from 1999/2000. DESIGN: The study was prospective and longitudinal, covering the period from reporting to military service to discharge. The outcome measure was the incidence of STS. Statistics from the military insurance system was analysed. STUDY SAMPLE: A total of 395 conscripts were included in the study (mean age 19 years). The control group (n: 839) consisted of men of the same age. RESULTS: In 2004/2005 the incidence rate of STS was 2.3% compared to 7.9% in 1999/2000 and compared to 3.7% among the controls. The number of cases of auditory complications reported from conscripts to the insurance system has decreased, from 16 to 5/100,000 days of military training, during the last decade. CONCLUSIONS: The new HCP apparently reduced the incidence rate of STS to one third compared to before the program was introduced and leveled it to the incidence rate in the control-group not exposed to military noise.

Age-related hearing decline in individuals with and without occupational noise exposure.

This study was conducted to compare the pattern of age-related hearing decline in individuals with and without self-reported previous occupational noise exposure. This was a prospective, population-based, longitudinal study of individuals aged 70-75 years, from an epidemiological investigation, comprising three age cohorts. In total there were 1013 subjects (432 men and 581 women). Participants were tested with pure tone audiometry, and they answered a questionnaire to provide information regarding number of years of occupational noise exposure. There were no significant differences in hearing decline, at any frequency, for those aged 70-75 years between the noise-exposed (N= 62 men, 22 women) and the nonexposed groups (N = 96 men, 158 women). This study supports the additive model of noise-induced hearing loss (NIHL) and age-related hearing loss (ARHL). The concept of different patterns of hearing decline between persons exposed and not exposed to noise could not be verified.

Cigarette- and snus-modified association between unprotected exposure to noise from hunting rifle caliber weapons and high frequency hearing loss. A cross-sectional study among swedish hunters.

AIM: To investigate in this cross-sectional study among Swedish hunters if tobacco use modifies the previously observed association, expressed as prevalence ratio (PR), between unprotected exposure to impulse noise from hunting rifle caliber (HRC) weapons and high-frequency hearing impairment (HFHI). SETTINGS AND DESIGN: A nationwide cross-sectional epidemiologic study was conducted among Swedish sport hunters in 2012. MATERIALS AND METHODS: The study was Internet-based and consisted of a questionnaire and an Internet-based audiometry test. RESULTS: In all, 202 hunters completed a questionnaire regarding the hearing test. Associations were modeled using Poisson regression. Current, daily use of tobacco was reported by 61 hunters (19 used cigarettes, 47 moist snuff, and 5 both). Tobacco users tended to be younger, fire more shots with HRC weapons, and report more hunting days. Their adjusted PR (1-6 unprotected HRC shots versus 0) was 3.2 (1.4-6.7), P < 0.01. Among the nonusers of tobacco, the corresponding PR was 1.3 (0.9-1.8), P = 0.18. P value for the interaction was 0.01. The importance of ear protection could not be quantified among hunters with HRC weapons because our data suggested that the HFHI outcome had led to changes in the use of such protection. Among hunters using weapons with less sound energy, however, no or sporadic use of hearing protection was linked to a 60% higher prevalence of HFHI, relative to habitual use. CONCLUSION: Tobacco use modifies the association between exposure to unprotected impulse noise from HRC weapons and the probability of having HFHI among susceptible hunters. The mechanisms remain to be clarified, but because the effect modification was apparent also among the users of smokeless tobacco, combustion products may not be critical for this effect.

Dietary habits and hearing.

UNLABELLED: Abstract Objective: Study groups from three age cohorts of 70-75 year-olds were investigated to search for possible correlations between dietary habits and auditory function. DESIGN: A cross-sectional, epidemiological study. STUDY SAMPLE: A total number of 524 people (275 women, 249 men) were recruited from three age cohorts. The study sample was representative of the general population. All participants answered a diet history and were tested with pure-tone audiometry. Eleven categories of food consumption were related to pure-tone averages of low-mid frequency hearing, and high frequency hearing. RESULTS: Two consistent correlations between diet and hearing were observed. One was a correlation between good hearing and a high consumption of fish in the male group. The other was a correlation between poor high frequency hearing and a high consumption of food rich in low molecular carbohydrates in both genders; a larger effect size was seen in females. CONCLUSIONS: The study indicates that diet is important for aural health in aging. According to this study fish is beneficial to hearing, whereas consumption of "junk food", rich in low molecular carbohydrates, is detrimental. Other correlations, e.g. between high consumption of antioxidants, were not demonstrated here, but cannot be excluded.

Shooting history and presence of high-frequency hearing impairment in swedish hunters: A cross-sectional internet-based observational study.

The aim of this cross-sectional study among Swedish hunters was to examine the association between shooting history and presence of high-frequency hearing impairment (HFHI). All hunters registered with an e-mail address in the membership roster of the Swedish Hunters' Association were invited via e-mail to a secure website with a questionnaire and an Internet-based audiometry test. Associations, expressed as prevalence ratio (PR), were multivariately modelled using Poisson regression. The questionnaire was answered by 1771 hunters (age 11-91 years), and 202 of them also completed the audiometry test. Subjective severe hearing loss was reported by 195/1771 (11%), while 23/202 (11%) exhibited HFHI upon testing with Internet-based audiometry. As many as 328/1771 (19%) had never used hearing protection during hunting. In the preceding 5 years, 785/1771 (45%), had fired >6 unprotected gunshots with hunting rifle calibers. The adjusted PR of HFHI when reporting 1-6 such shots, relative to 0, was 1.5 [95% confidence interval (CI) 1.1-2.1; P = 0.02]. We could not verify any excessive HFHI prevalence among 89 hunters reporting unprotected exposure to such gunshot noise >6 times. Nor did the total number of reported rifle shots seem to matter. These findings support the notion of a wide variation in individual susceptibility to impulse noise; that significant sound energy, corresponding to unprotected noise from hunting rifle calibers, seems to be required; that susceptible individuals may sustain irreversible damage to the inner ear from just one or a few shots; and that use of hearing protection should be encouraged from the first shot with such weapons.

Sickness absence and disability pension due to otoaudiological diagnoses: risk of premature death--a nationwide prospective cohort study.

BACKGROUND: It is estimated that hearing difficulties will be one of the top ten leading burdens of disease by 2030. Knowledge of mortality among individuals on sick leave or disability pension due to hearing diagnoses is virtually non-existent. We aimed prospectively to examine the associations of diagnosis-specific sick leave and disability pension due to different otoaudiological diagnoses with risks of all-cause and cause-specific mortality. METHODS: A cohort, based on Swedish registry data, including all 5,248,672 individuals living in Sweden in 2005, aged 20-64, and not on old-age pension, was followed through 2010. Otoaudiological diagnoses were placed in the following categories: otological, hearing, vertigo, and tinnitus. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazard models; individuals on sick leave or disability pension due to different otoaudiological diagnoses during 2005 were compared with those not on sick leave or disability pension. RESULTS: In multivariable models, individuals with sickness absence due to otoaudiological diagnoses showed a lower risk of mortality, while individuals on disability pension due to otoaudiological diagnoses showed a 14% (95% CI 1-29%) increased risk of mortality, compared with individuals not on sick leave or disability pension. The risk increase among individuals on disability pension was largely attributable to otological (HR 1.56; 95% CI = 1.04-2.33) and hearing diagnoses (HR 1.20; 95% CI = 1.00-1.43). CONCLUSION: This large nationwide population-based cohort study suggests an increased risk of mortality among individuals on disability pension due to otoaudiological diagnoses.

Sickness absence due to otoaudiological diagnoses; a descriptive nationwide study.

BACKGROUND: Hearing difficulties constitute a large public health problem. Knowledge about their consequences in terms of sickness absence due to otoaudiological diagnoses is very scarce. The aim of this study was to gain such knowledge. Both individuals with sick leave due to otoaudiological diagnoses and sick-leave spells due to these diagnoses were examined, in a nationwide setting. METHODS: Through Swedish nationwide registers we identified all 4768 individuals, aged 16-64 years and living in Sweden who were sickness absent due to otoaudiological diagnoses (ICD10; H60-H95) in 2005. We described the demographic characteristics of these individuals, as well as aspects regarding prevalence and duration of such sick-leave spells, in general and in four specific diagnosis groups; otological, hearing, vertigo, and tinnitus. RESULTS: Sick leave due to otoaudiological diagnoses was more common among women in all diagnosis groups except with tinnitus. Individuals with a hearing or tinnitus sick-leave diagnosis had a higher educational level and were hospitalized fewer days compared to those sickness absent due to vertigo or otological diagnoses. Particularly, sick-leave spells due to hearing or tinnitus diagnoses tended to be long, in many cases lasting the entire year. The majority of the individuals only had one sick-leave spell in 2005. CONCLUSIONS: Although the actual number of individuals with a sick-leave spell due to specific otoaudiological diagnosis might not be considered high, the high prevalence of long sick-leave spells due to particularly hearing and tinnitus diagnoses indicates the importance of preventive and rehabilitative actions.

Hearing of 75-year old persons over three decades: has hearing changed?

OBJECTIVE: The state of hearing in 75-year old persons was measured in a population based epidemiological study with the aim of studying if hearing had changed during a time span of 29 years. DESIGN: An epidemiological study of generational effects in three age cohorts. STUDY SAMPLE: Three age cohorts were included: cohort 1 (n: 267) born in 1976-77, cohort 4 (n: 197) in 1990-91, and cohort 6 (n: 570) in 2005. The same test procedures using pure-tone audiometry and a short questionnaire were applied to the three cohorts of 75-year old residents in the same city. RESULTS: The hearing was essentially unchanged during the span of the investigation-almost three decades. Low-frequency hearing was up to about 10 dB poorer in the most recently studied cohort compared to the previously studied cohorts. The reason for this difference is considered to depend on methodological factors. Self-assessed hearing and tinnitus was mainly unchanged, or had minor changes both to the better and to the worse. CONCLUSIONS: The hearing, both measured with pure-tone audiometry and with a short questionnaire, of 75-year old persons has not changed at all, or only marginally, over three decades.

Pathophysiological and Clinical Aspects of Hearing Loss Among 85-Year-Olds.

PURPOSE: This study aimed to identify the prevalence of conductive/mixed and sensorineural hearing loss, with an attempt to differentiate between sensory and neural components in 85-year-olds. METHOD: A comprehensive auditory test protocol, including pure-tone audiometry, speech audiometry, auditory brainstem response (ABR), and distortion product otoacoustic emission (DPOAE), was used to identify different types of hearing loss in 85-year-olds. This study comprised a subsample (n = 125) selected from an unscreened cohort of 85-year-olds born in 1930, within the Gothenburg H70 Birth Cohort Studies in Sweden. RESULTS: Test results were reported descriptively. Sensorineural hearing loss was present in one or both ears in almost all participants (98%), and the majority had absent DPOAEs. Only approximately 6% had additional conductive hearing loss, that is, mixed hearing loss. Approximately 20% of the participants with a pure-tone average at 0.5-4 kHz < 60 dB HL had worse word recognition scores compared with predicted scores by the Speech Intelligibility Index (SII), whereas only two participants were classified with neural dysfunction with the use of ABR. CONCLUSIONS: Sensorineural hearing loss, likely related to outer hair cell loss, was present in the vast majority of 85-year-olds. Conductive/mixed hearing loss appears to be relatively rare in advanced age. Poor word recognition scores in relation to SII-predicted scores were relatively common (20%) in 85-year-olds, whereas auditory neuropathy was only rarely identified (1.6%) by the use of ABR latencies. To explain abnormal word recognition and to identify the neural component of hearing loss among the older-old population, future research should consider factors such as listening effort and cognition among the older-old population.

Central auditory function in early Alzheimer's disease and in mild cognitive impairment.

OBJECTIVE: to investigate auditory function in subjects with early Alzheimer's disease, mild cognitive impairment and with subjective memory complaints, in search of signs of central auditory processing dysfunction even in early stages of cognitive impairment. DESIGN AND SUBJECTS: a consecutive group of men and women, referred to the Memory Clinic at the Karolinska University Hospital, was approached for inclusion in this prospective study. One hundred and thirty-six subjects, mean age 64 years (range 50-78 years), diagnosed with Alzheimer's disease (n = 43), mild cognitive impairment (n = 59) or with subjective memory complaints (n = 34), were included. METHODS: auditory function was assessed with pure tone audiometry, speech perception in quiet and in background noise and dichotic digits tests with two or three digits. RESULTS: pure tone audiometry and speech perception scores in quiet and in background noise were normal for age and without between-group differences. Dichotic digits tests showed strongly significant differences between the three groups, where the Alzheimer's disease group performed significantly poorer than the other two groups, with the mild cognitive impairment group in an intermediate position. CONCLUSIONS: our results demonstrate that central auditory processing dysfunction is highly evident in subjects with Alzheimer's disease, and to a considerable extent even in subjects with mild cognitive impairment.