Patterns of hearing changes in women and men from denarians to nonagenarians

The effect of aging and asymmetrical hearing on speech discrimination

BACKGROUND

Speech discrimination (SpD) is exacerbated by hearing loss, but the relationship between pure-tone audiometry (PTA) and SpD is poorly described and understood in the aging process. It is also unclear whether severity of left-right (L-R) differences in PTA threshold disproportionately affects SpD.

METHODS

We conducted a retrospective cross-sectional study of a broad age range (10-99 years) of patients in Japan. Demographic data, SpD, and PTA threshold data were collected for each patient and side (L-R). We evaluated the association between chronological age and overall SpD, and SpD according to severity of PTA-threshold difference for ear pairs. Asymmetries in L-R PTA thresholds were stratified into four equally spaced categories: <10dB L-R difference to ≥40 dB L-R difference.

RESULTS

Among the 2760 eligible participants, data from 5508 ears are analyzed. Overall SpD gradually decreases with age, with SpD scores in the oldest groups being significantly worse (Kruskal-Wallis followed by Dunn's test; p < 0.0001) than those of the youngest group. Comparison of worse-hearing ears to better-hearing ears within the same severity of hearing impairment reveals significant differences on SpD in ears that have moderate or severe hearing impairment (p < 0.0001). Post-hoc analysis identifies significant differences in SpD between the worse-hearing ears and the better-hearing ears that have hearing differences of 20 dB or more.

CONCLUSIONS

SpD is dramatically affected by age and asymmetrical hearing. Therefore, appropriate audiological interventions should be proactively considered according to an individual's hearing level, age, and difference in L-R hearing levels.

Effect of age-related extended high frequency hearing loss on the subjective impressions of dental drill noise

Fear and anxiety among patients are sometimes evoked in dental clinics due to the sound of dental drills. This study aimed to explore the impact of age-related hearing loss in the extended high frequency (EHF) range above 8 kHz on individuals' subjective discomfort towards dental drill noise. After measuring pure-tone audiometric thresholds at both conventional and extended high frequencies, we used a psychoacoustic approach to evaluate subjective impressions of four dental drill sound stimuli, which featured varying frequency components, in 62 participants (aged 12-67 years). We found a significant decrease in hearing sensitivity within the EHF range as age increased, with notable differences in hearing thresholds at 14 kHz between teenage and older adults exceeding 65 dB. Furthermore, significant differences were observed between younger and older (above 40 years) participants in the subjective impressions of dental drill noise, emphasizing age as a critical factor in the perception of high frequency components. Consequently, age may influence the unpleasantness of dental drilling noise. Compared to older individuals, young participants may exhibit increased fear of dental procedures owing to physiological factors. These results underscore the need for age-appropriate noise control strategies in dental clinics to mitigate anxiety and improve patient comfort.

Trends in Distributions of Hearing Threshold Levels by Ages: A Comparison of the ISO 7029 and Newly Available Country-Specific Data

Hearing thresholds provide essential information and references about the human auditory system. This study aimed to identify changing trends in distributions of hearing threshold levels across ages by comparing the International Organization for Standardization (ISO) 7029 and newly available data after publishing ISO 7029. To compare ISO 7029 and newly available hearing threshold data after publishing ISO 7029, four country-specific datasets that presented average hearing threshold levels under conditions similar to ISO 7029 were utilized. For frequencies between 125 Hz and 8,000 Hz, the deviations of hearing threshold values by ages from the hearing threshold of the youngest age group for each data point were utilized. For frequencies from 9,000 Hz to 12,500 Hz, the median threshold information was utilized. Hearing threshold data reported after publishing ISO 7029 from the four countries were mostly similar to the ISO 7029 data but tended to deviate in some age groups and sexes. As national hearing threshold trends change, the following ISO 7029 revision suggests the need to integrate hearing threshold data from different countries.

Fatty acid binding protein type 7 deficiency preserves auditory function in noise-exposed mice

Fatty acid-binding protein 7 (FABP7) is vital for uptake and trafficking of fatty acids in the nervous system. To investigate the involvement of FABP7 in noise-induced hearing loss (NIHL) pathogenesis, we used Fabp7 knockout (KO) mice generated via CRISPR/Cas9 in the C57BL/6 background. Initial auditory brainstem response (ABR) measurements were conducted at 9 weeks, followed by noise exposure at 10 weeks. Subsequent ABRs were performed 24 h later, with final measurements at 12 weeks. Inner ears were harvested 24 h after noise exposure for RNA sequencing and metabolic analyses. We found no significant differences in initial ABR measurements, but Fabp7 KO mice showed significantly lower thresholds in the final ABR measurements. Hair cell survival was also enhanced in Fabp7 KO mice. RNA sequencing revealed that genes associated with the electron transport chain were upregulated or less impaired in Fabp7 KO mice. Metabolomic analysis revealed various alterations, including decreased glutamate and aspartate in Fabp7 KO mice. In conclusion, FABP7 deficiency mitigates cochlear damage following noise exposure. This protective effect was supported by the changes in gene expression of the electron transport chain, and in several metabolites, including excitotoxic neurotransmitters. Our study highlights the potential therapeutic significance of targeting FABP7 in NIHL.

Subjective and Objective Hearing Loss Among US Adult Cancer Survivors

Importance

Cancer survivors are at a higher risk of developing hearing loss (HL) due to older age, chemotherapy, and radiotherapy. However, the prevalence of HL among US cancer survivors remains unknown. Additionally, there is a lack of uniform HL screening guidelines for this enlarging population.

Objective

To estimate the prevalence of subjective HL and objective HL by audiometry test among cancer survivors and compare them with the general population as well as to assess the performance of subjective HL questions in detecting true (ie, audiometry-confirmed) HL.

Design, Setting, and Participants

In a cross-sectional design, adults between ages 20 and 80 years who had audiometry testing and responded to a hearing questionnaire from the National Health and Nutrition Examination Survey (2011-2012, 2015-2016, and 2017 to March 2020 prepandemic survey cycles) were selected. Data analysis was conducted from August 13, 2022, to July 26, 2023.

Main Outcomes and Measures

The weighted prevalence of subjective HL (troublesome hearing and tinnitus) and objective HL (speech-frequency HL and high-frequency HL) by audiometry were calculated. Analyses with χ2 testing and multiadjusted logistic regression models were used to compare HL between cancer survivors and the general population. To evaluate the performance of subjective HL questions as a tool to screen for objective HL by audiometry, areas under the curve were estimated using age- and gender-adjusted logistic regression.

Results

Among the total 9337 participants (weighted n = 90 098 441; 51.2% women), 10.3% were cancer survivors. Compared with the general population, cancer survivors had a higher prevalence of troublesome hearing (adjusted odds ratio [AOR], 1.43; 95% CI, 1.11-1.84), tinnitus (AOR, 1.28; 95% CI, 0.94-1.74), speech-frequency HL (AOR, 1.43; 95% CI, 1.11-1.85), and high-frequency HL (AOR, 1.74; 95% CI, 1.29-2.34). When using the subjective HL tool and questioning regarding whether the participants were having troublesome hearing and/or tinnitus in screening for HL, the age- and gender-adjusted area under the curve was 0.88 in detecting speech-frequency HL and 0.90 in detecting high-frequency HL.

Conclusion and Relevance

The findings of this study suggest that cancer survivors have a significantly higher prevalence of HL than the general population. Two subjective HL questions could potentially accurately identify those who have true HL and provide a simple and efficient screening tool for health care professionals. Cancer survivors and their families should be educated and encouraged to discuss hearing concerns, and health care professionals should facilitate raising awareness and provide early screening and timely referral when HL is identified.

Blood levels of nicotinic acid negatively correlate with hearing ability in healthy older men

BACKGROUND

Age-related hearing loss (ARHL) is a common phenomenon observed during aging. On the other hand, the decrease in Nicotinamide adenine dinucleotide (NAD +) levels is reported to be closely related to the age-related declines in physiological functions such as ARHL in animal studies. Moreover, preclinical studies confirmed NAD + replenishment effectively prevents the onset of age-related diseases. However, there is a paucity of studies on the relationship between NAD⁺ metabolism and ARHL in humans.

METHODS

This study was analyzed the baseline results of our previous clinical trial, in which nicotinamide mononucleotide or placebo was administered to 42 older men (Igarashi et al., NPJ Aging 8:5, 2022). The correlations between blood levels of NAD⁺-related metabolites at baseline and pure-tone hearing thresholds at different frequencies (125, 250, 500, 1000, 2000, 4000, and 8000 Hz) in 42 healthy Japanese men aged > 65 years were analyzed using Spearman's rank correlation. Multiple linear regression analysis was performed with hearing thresholds as the dependent variable and age and NAD⁺-related metabolite levels as independent variables.

RESULTS

Positive associations were observed between levels of nicotinic acid (NA, a NAD⁺ precursor in the Preiss-Handler pathway) and right- or left-ear hearing thresholds at frequencies of 1000 Hz (right: r = 0.480, p = 0.001; left: r = 0.422, p = 0.003), 2000 Hz (right: r = 0.507, p < 0.001, left: r = 0.629, p < 0.001), and 4000 Hz (left: r = 0.366, p = 0.029). Age-adjusted multiple linear regression analysis revealed that NA was an independent predictor of elevated hearing thresholds (1000 Hz (right): p = 0.050, regression coefficient (β) = 1610; 1000 Hz (left): p = 0.026, β = 2179; 2000 Hz (right): p = 0.022, β = 2317; 2000 Hz (left): p = 0.002, β = 3257). Weak associations of nicotinic acid riboside (NAR) and nicotinamide (NAM) with hearing ability were observed.

CONCLUSIONS

We identified negative correlations between blood concentrations of NA and hearing ability at 1000 and 2000 Hz. NAD⁺ metabolic pathway might be associated with ARHL onset or progression. Further studies are warranted.

TRIAL REGISTRATION

The study was registered at UMIN-CTR (UMIN000036321) on 1st June 2019.

Prevalence of Hearing Impairment by Age: 2nd to 10th Decades of Life

Background: Accurate data on the prevalence of hearing impairment and severity across age and gender are paramount to formulate hearing health policies. Here, we sought to analyze audiometric data from a large group of age-diverse people in Japan, which has not been previously described in detail. Methods: We analyzed retrospective hearing threshold data of 23,860 participants (10−99 years; left-right hearing threshold difference <15 dB; air-bone gap ≤10 dB) at 500, 1000, 2000, and 4000 Hz, and then classified them for hearing impairment severity according to the WHO Classification. Findings: There was a significant gender difference in median hearing thresholds, starting in 20-year-olds up to early 80-year-olds. Twenty-five percent of men in their late 50s had some level of HI, ~50% in their late 60s, and ~75% in their late 70s. For women, 25% had some level of HI in their early 60s, ~50% in their early 70s, and ~75% in their late 70s. For participants in their early 80s, 50% of either gender had moderate or more severe HI. Interpretation: Our results, derived from a large number of participants, provide basic information about the prevalence of hearing loss by age decade. Since people can expect to live longer than those in previous generations, our detailed data can inform national social systems responsible for hearing screening in making decisions about hearing-aid qualification, which may reduce barriers to older people’s independence, productivity, and quality of life.

The Impact of COVID-19 Confinement on Tinnitus and Hearing Loss in Older Adults: Data From the LOST in Lombardia Study

Background

Although a direct relationship between tinnitus or hearing difficulties and COVID-19 has been suggested, current literature provides inconsistent results, and no research has been undertaken in older adults.

Methods

In November 2020, we conducted the LOST in Lombardia survey, a telephone-based cross-sectional study on a sample of 4,400 individuals representative of the general population aged ≥65 years from Lombardy region, Northern Italy. Individuals with diagnosed tinnitus and/or hearing loss were asked whether their conditions had improved or deteriorated in 2020 compared to 2019.

Results

Overall, 8.1% of older adults reported a diagnosis of tinnitus and 10.5% of hearing loss. In 2020 compared to 2019, among individuals with tinnitus, those with increasing severity (5.0%) were similar to those decreasing it (5.3%). Among individuals with hearing loss, more people reported an increase (13.6%) than a decrease (3.2%) in their disease severity. No individual with a diagnosis in 2020 of tinnitus (n = 6) or hearing loss (n = 13) had COVID-19. The incidence of tinnitus was lower in 2020 (rate: 14.8 per 10,000 person-years) than in previous years (rate in 1990–2019: 36.0 per 10,000 person-years; p = 0.026). There was no change in the incidence of hearing loss (p = 0.134).

Conclusions

In this large representative sample of older adults, on average neither COVID-19 confinement nor SARS-CoV-2 infection appeared to increase the severity or incidence of tinnitus. The increased severity of hearing difficulties may totally or partially be explained by physiologic deterioration of the condition, or by a misperception due to the use of face-masks.