Worse Self-Reported Hearing Ability Is Associated With Greater Perceived Physical and Mental Fatigability

Older adults with hearing loss often report higher fatigue due to effortful listening. We evaluated whether self-reported hearing ability is associated with perceived physical and mental fatigability (a more sensitive measure than fatigue) using the Pittsburgh Fatigability Scale (PFS). Older adults (N=2,558) from the Long Life Family Study Visit 2 (71.5±11.4 years; 54.8% women) completed PFS and self-reported hearing ability (worse=[fair,poor,very poor,deaf] or better=[good, excellent]). Age-adjusted PFS Physical and Mental scores were 2.3 and 2.5 lower, respectively, for worse vs. better hearing (p<.0001). Generalized estimating equations adjusted for family-relatedness, site, age, sex, cognitive function (Mini-Mental State Examination), education, and self-reported health. Compared to individuals with better hearing, those with worse hearing had a 42% and 44% greater odds of physical (≥15) (CI:1.12-1.80,p=0.0042) and mental(≥13) (CI:1.13-1.84,p=0.0034) fatigability, respectively. These observed associations may potentially be explained via complex psychosocial and cognitive aging pathways (e.g. effortful listening) to be examined in future work.

Normative Data for the CERAD-NP for Healthy High-Agers (80–84 years) and Effects of Age-Typical Visual Impairment and Hearing Loss

Objectives: This study aims to establish reference data for nondemented adults between 80 and 84 years of age based on the German version of the Consortium to Establish a Registry for Alzheimer’s disease Neuropsychological (CERAD-NP) test battery and to assess the possible influence of hearing and vision impairments on CERAD-NP performance. Methods: Two hundred one volunteers were examined with the German CERAD-NP test battery, and 18 test scores were calculated from the data. The sample included 99 men (49%), the mean age was 81.8 years (SD = 1.3), and the mean years of education were 13.9 (SD = 3.1). Percentiles for continuous and percentile ranks for discrete test scores were calculated separately for four norm groups. The groups were classified according to gender and education. Multiple regression analysis was used to predict cognitive performance from visual acuity and hearing ability. Results: The normative data obtained were consistent with other findings from younger and older age groups. Worse visual acuity predicted slower performance in the Trail Making Test (TMT). None of the other CERAD-NP tests were correlated to sensory functions. Conclusions: Using age-appropriate reference data, such as that established here for the 80–84 year age group can help to improve the detection of cognitive decline and prevent biases that arise when old-old adults are compared to younger old adults. Visual acuity should be considered an influencing factor on TMT performance.

Whole-genome sequence analysis unveils different origins of European and Asiatic mouflon and domestication-related genes in sheep

The domestication and subsequent development of sheep are crucial events in the history of human civilization and the agricultural revolution. However, the impact of interspecific introgression on the genomic regions under domestication and subsequent selection remains unclear. Here, we analyze the whole genomes of domestic sheep and their wild relative species. We found introgression from wild sheep such as the snow sheep and its American relatives (bighorn and thinhorn sheep) into urial, Asiatic and European mouflons. We observed independent events of adaptive introgression from wild sheep into the Asiatic and European mouflons, as well as shared introgressed regions from both snow sheep and argali into Asiatic mouflon before or during the domestication process. We revealed European mouflons might arise through hybridization events between a now extinct sheep in Europe and feral domesticated sheep around 6000–5000 years BP. We also unveiled later introgressions from wild sheep to their sympatric domestic sheep after domestication. Several of the introgression events contain loci with candidate domestication genes (e.g., PAPPA2, NR6A1, SH3GL3, RFX3 and CAMK4), associated with morphological, immune, reproduction or production traits (wool/meat/milk). We also detected introgression events that introduced genes related to nervous response (NEURL1), neurogenesis (PRUNE2), hearing ability (USH2A), and placental viability (PAG11 and PAG3) into domestic sheep and their ancestral wild species from other wild species.

Impact of Occupational Noise on Hearing Threshold Profile Among Male Industrial Workers

With respect to population growth, there will inevitably be an increasing need for improvements in technology, which has led to greater energy efficiency, higher labour efficiency, continuous production methods and operating flexibility; in addition to these factors, mechanisation has also advanced rapidly. It has been also been reported that the introduction of louder machines with the process of industrialisation has made noise a major occupational and environmental hazard. Against this backdrop, a study has been conducted to assess the impact of occupational noise, if any, on the hearing status of human resources occupationally engaged in the industry. A total of 57 male volunteers, aged between 25 and 39 years, working at least for a period of 5 years, constituted the exposed group. A total of 36 individuals of comparable age working in administrative office constituted the control group. Hearing impairment was calculated at speech frequency, up to 4 kHz and up to 6 kHz. The degree of hearing impairment was also calculated. From the present study, it may be concluded that the hearing ability of the human resources, engaged in different sections of the industry, is significantly impaired compared to their age matched counterparts.

Neural correlates of masked and unmasked tones: psychoacoustics and late auditory evoked potentials (LAEPs)

Hearing thresholds can be used to quantify one's hearing ability. In various masking conditions, hearing thresholds can vary depending on the auditory cues. With comodulated masking noise and interaural phase disparity (IPD), target detection can be facilitated, lowering detection thresholds. This perceptual phenomenon is quantified as masking release: comodulation masking release (CMR) and binaural masking level difference (BMLD). As these measures only reflect the low limit of hearing, the relevance of masking release at supra-threshold levels is still unclear. Here, we used both psychoacoustic and electro-physiological measures to investigate the effect of masking release at supra-threshold levels. We investigated whether the difference in the amount of masking release will affect listening at supra-threshold levels. We used intensity just-noticeable difference (JND) to quantify an increase in the salience of the tone. As a physiological correlate of JND, we investigated late auditory evoked potentials (LAEPs) with electroencephalography (EEG). The results showed that the intensity JNDs were equal at the same intensity of the tone regardless of masking release conditions. For LAEP measures, the slope of the P2 amplitudes with a function of the level was inversely correlated with the intensity JND. In addition, the P2 amplitudes were higher in dichotic conditions compared to diotic conditions. Estimated the salience of the target tone from both experiments suggested that the salience of masked tone at supra-threshold levels may only be beneficial with BMLD.

Personality captures dissociations of subjective versus objective hearing in noise

Acoustic noise is pervasive in human environments. Some individuals are more tolerant to noise than others. We demonstrate the explanatory potential of Big-5 personality traits neuroticism (being emotionally unstable) and extraversion (being enthusiastic, outgoing) on subjective self-report and objective psycho-acoustic metrics of hearing in noise in two samples (total N = 1103). Under statistical control for demographics and in agreement with pre-registered hypotheses, lower neuroticism and higher extraversion independently explained superior self-reported noise resistance, speech-hearing ability and acceptable background noise levels. Surprisingly, objective speech-in-noise recognition instead increased with higher levels of neuroticism. In turn, the bias in subjectively overrating one's own hearing in noise decreases with higher neuroticism but increases with higher extraversion. Of benefit to currently underspecified frameworks of hearing in noise and tailored audiological treatments, these results show that personality explains inter-individual differences in coping with acoustic noise, which is a ubiquitous source of distraction and a health hazard.

Hearing Ability of Prairie Voles (Microtus ochrogaster)

Hearing ability of mammals can be impacted by many factors including social cues, environment, and physical properties of animal morphology. Despite being used commonly to study social behaviors, the hearing ability of the monogamous prairie vole (Microtus ochrogaster) has never been fully characterized. In this study, we measure morphological head and pinna features and use auditory brainstem responses to measure hearing ability of prairie voles characterizing monaural and binaural hearing and hearing range. Additionally, we measured unbonded male and female voles to characterize differences due to sex. We found that prairie voles have intermediate hearing ability with an optimal hearing range of 8 to 32 kHz, robust binaural hearing ability, and characteristic monaural ABRs. We show no differences between the sexes for binaural hearing or hearing range, however female voles have increased amplitude of peripheral ABR waves I and II and increased latency of wave IV. Our results confirm that prairie voles have both low and high frequency hearing, binaural hearing capability, and despite biparental care and monogamy, differences in processing of sound information between the sexes. These data further highlight the necessity to understand sex-specific differences in neural processing that may underly variability in behavioral responses between sexes.