The marked increase in the number of persons with dementia and hearing impairment in the era of the super-aged society in Japan is an urgent social problem. In this review, the government policies for the prevention of dementia are outlined, and the relationship between dementia and age-related hearing loss, and the role of hearing aid use in the prevention of dementia are discussed with a review of the related literature.

　　Existence of a relationship between hearing impairment (HI) and disability or dementia has been reported in older adults, and there is growing evidence to suggest that HI may be an independent modifiable risk factor for dementia. Nevertheless, there is insufficient evidence to recommend the use of hearing aids to reduce the risk of cognitive decline. To address these issues, we are currently conducting a clinical study, in cooperation with neurologists, gerontologists, and otorhinolaryngologists, to investigate the association between cognitive function and HI in older adults. As part of this study, we also investigated such association, using data from healthcare check-up programs for community dwellers.

　　We analyzed the data 1602 eligible participants. Hearing aid users were older and less likely to be suffering from cognitive impairment than non-hearing aid users. Multivariate logistic regression analysis showed that HI was independently associated with an inability to correctly draw a clock (odds ratio 1.60, 95% confidence interval 1.12-2.26). As compared to the case in other Western countries, the rate of use of hearing aids in Japan is lower, although the percentage of older adults with HI was similar to that in Western countries. Both otorhinolaryngologists and geriatricians should be alert for the potential presence of HI in older adults.

　　We investigated the data of 19 children with bilateral hearing loss in whom hearing in one ear had been passed (false-negative result) by automated auditory brainstem response in newborn hearing screening (NHS). Five children had a family history of hearing loss. Seven of the 15 children who had undergone screening multiple times had failed in both ears at least once. Detailed audiological examinations revealed that seven children had mild, 11 children had moderate, and one child had severe hearing loss in the passed ear. In most children, the hearing impairment was of a similar degree in both ears. The reasons for the false-negative result in the NHS were deduced to be, i) hearing level close to the detection limit of NHS in 11 children, ii) normal hearing level at high frequencies in six children, iii) progressive hearing impairment in one child, and unknown in one child. Hearing aid use was recommended in 18 children, however, four refused hearing aids or discontinued their visits. Even in children who pass NHS in one ear, more precise audiological examinations and careful management are necessary. Particular attention is needed especially in cases with a family history of hearing loss, experience of bilateral failure on at least one occasion in the course of multiple screenings, or mild to moderate hearing loss or a special hearing type in the contralateral other ear.

　　The results of emotional understanding tasks were examined in 45 children with hearing loss (average age, 10 years 4 months) and 232 children of the same age without hearing loss (average age 9 years 10 months). The task conditions consisted of two types of conversational situations that evoked positive and negative emotions, and two perspectives of the character and the target child. They were asked about emotional perception and emotional explanation in the conversational scenes. The results revealed that children with hearing loss showed reduced sharing of emotional perceptions of negative emotional situations. Their emotional explanation involved elements of verbal ability. The results of this study indicate that it is important to focus on the emotional aspects of conversation, add explanations, and promote emotional understanding to support language development in children with hearing loss.

　　The aim of this study was to clarify the effects of hearing aid use on frailty. The subjects were 64 outpatients of a hearing clinic aged 60 years old or older who had no previous history of use of hearing aids. We evaluated the patients' performance on the Kihon Checklist (KCL) before and about 6 months after the subjects started to use hearing aids. There was no significant change in the overall KCL score after the subjects started to use hearing aids. The response to only one question of the KCL, namely, “Do you travel in buses or trains?” showed significant improvement after the subjects had started to use hearing aids. We comparatively analyzed the characteristics (age, sex, average thresholds of the better hearing ear, speech recognition, KCL score, and patient-related consultation) between the KCL-improved and non-improved groups, and found that higher KCL scores and better hearing before the start of hearing aid use were significantly associated with improvement of the KCL score. We also comparatively analyzed the characteristics between the KCL-worsened and non-worsened groups, which revealed no significant differences. Hearing aid use had no effect on the overall degree of frailty, however, improvement of one item of IADL was observed, and there was one patient who showed improvement from frail to robust after they started using hearing aids. Therefore, hearing aid use is considered as one of the approaches for the elderly with hearing impairment and frailty.

　　We examined the development of oral communication and the language progress in patient groups with moderate/severe hearing loss and patients with profound hearing loss who had been started on rehabilitation by the teaching method using oral communication. The subjects were the following 6 cases. In the 124 patients who had received guidance, hearing aid use had been initiated 5 to 6 months after birth, and there were no obvious disorders other than hearing and no fluctuation or deterioration of hearing, and no abnormalities were observed in the middle or inner ear. The development was compared in five stages: 1) vocalization imitation, 2) word imitation, 3) two-word chain imitation, 4) positive/negative decision making, and 5) completion of 5W1H, which was the aim of this instruction. The results revealed that while cochlear implant surgery was performed at an average of 2 years 2 months of age in the group with profound hearing impairment, there was a delay of more than 1 year 4 months before the final stage was reached as compared to the groups with moderate/severe hearing impairment.

　　However, the VIQ results at age 10 were similar in both groups. It was also shown that hearing impairment affects the early development of oral communication as compared to the case in the language development of normal children. Our findings suggest that long-term observation, personalized care and medical care are necessary for voice communication and language development in hearing-impaired children.

　　Early detection of congenital deafness, early treatment, and cochlear implantation at an early age have led to improvements in the hearing ability, language development, and communication skills of children with hearing loss. Also, the number of hearing-impaired children who have received inclusive education in local regular schools has increased in recent years, although various problems have been pointed out. We conducted a questionnaire survey to examine the actual problems of school life in 89 persons with bilateral hearing loss who had received inclusive education from 5th grade to 25 years of age.

　　Most of the hearing-impaired persons had troubles during classes, especially classes that involved group learning, noise, and listening from a distance. They also had problems in learning subjects such as English, music, physical education, and problems in developing/maintaining friendships. The higher the degree of hearing loss, the more frequent pronounced? the problems were.

　　It is necessary to accurately grasp the situation and problems in each individual's school life and to cooperate with promote collaboration between medical care and education. In addition, the need for personalized interventions, such as communication using visual information, support staff assignment, learning support, and an approach attention to the psychological burden by experts, is suggested.

　　In this study, we investigated speech transmission and the sound environment in an Ear, Nose and Throat (ENT) hospital, considering three categories: a “vocal system” by the hospital staff, a “transmission system” with noise and reverberation, and a “listening system” by outpatients. First, we conducted a questionnaire survey among outpatients and staff in the waiting and consultation rooms of the ENT hospital. Second, we measured the noise level and reverberation time in the two rooms. Our findings confirmed that hearing-impaired outpatients had trouble responding when their names were called at the hospital reception. The inconvenience problem was more marked for outpatients with a higher degree of hearing loss. Many of the staff thought that this was caused by noise and their hearing loss, and made an effort to speak slowly, clearly and loudly when explaining anything to the outpatients. However, many of the staff also felt that there was a lot of noise in the rooms, and the measured noise level of the waiting room and consultation room indeed exceeded the allowable value.