Currently, genetic testing for hearing loss, including congenital hearing loss and young adult-onset bilateral sensorineural hearing loss, is reimbursed by the social health insurance system in Japan. Most infants with congenital hearing loss visit specialized facilities, such as institutions that perform precise hearing testing. In more than half of the cases, congenital hearing loss is caused by hereditary hearing loss inherited, and genetic testing to diagnose the cause is becoming more common. In contrast, although acquired/late-onset hearing loss can be associated with hereditary hearing loss, patients visit a variety of medical institutions that do not necessarily specialize in hearing loss. In order to make an accurate diagnosis of hearing loss regardless of the medical institution that a subject visits, it is important to bear in mind the possibility of a genetic cause based on the clinical course and audiogram. In patients with (1) acquired/late-onset bilateral sensorineural hearing loss starting before the age of 40, and those with (2) bilateral sensorineural hearing loss starting after the age of 40 that cannot be explained as age-related hearing loss, it is important to obtain the family history and determine the associated symptoms, and create a family tree. Based on these, the inheritance pattern and possibility of syndromic hearing loss is estimated, and then the necessity of genetic testing should be considered.

　 Some cases of juvenile bilateral sensorineural hearing loss exhibit high-frequency sensorineural hearing loss similar to presbycusis due to genetic factors, so it is considered that there are a certain number cases of juvenile bilateral sensorineural hearing loss diagnosed as presbycusis.

　 We present the process from detailed examination through genetic testing at a university hospital, to intervention with electric acoustic stimulation (EAS) based on the results of the audiogram and subsequent genetic testing. In cases where genetic testing is recommended for suspected juvenile sensorineural hearing loss, obtaining the family history, as in the presented cases, is of utmost importance in addition to the diagnostic criteria. In the case of juvenile bilateral sensorineural hearing loss, autosomal dominant inheritance is common and a family history is often present. In such cases, the information obtained through genetic testing and hearing genetic counseling is significant, and wider utilization of genetic testing is expected.

　 A 50-year-old woman with progressive bilateral moderate hearing loss visited our outpatient clinic. Her mother and elder and younger sisters also had hearing loss, and the elder sister died of diabetic kidney disease. Genetic testing revealed mitochondrial m.3243>G. The same mutation was also identified in her daughter, who, however, showed normal hearing. They have no signs/symptoms of diabetes mellitus so far, and are taking good care to prevent the onset of the disease. Genetic testing can be performed at clinics and should be performed in patients presenting with hearing loss.

　 In general, it is said that even if hearing aid use is recommended, patients with unilateral sensorineural hearing loss often do not use hearing aids. We investigated the effectiveness of hearing aids for patients who were aware of the inconvenience and pain caused by tinnitus and the disability caused by unilateral sensorineural hearing loss and visited our department between November 2006 and June 2022 wishing to be fitted with hearing aids to improve their hearing loss. The unilateral hearing loss was sudden in onset in the majority of cases, and there were no cases of congenital hearing loss. After 3 months, 92% of the patients purchased hearing aids. The results showed that some conversational intelligibility could be expected with the use of hearing aids for those with moderate hearing loss, but not for those with severe hearing loss. The THI scores improved significantly regardless of the hearing level.

　 Because the benefits of using these hearing aids cannot be experienced until the hearing aids are actually tried, patients with unilateral sensorineural hearing loss who are inconvenienced and troubled should be provided with information about hearing aids, including its predicted benefits, and given the opportunity to try hearing aids, regardless of their hearing level.

　 During the 5-year period from January 2015 to December 2019, 32 nonagenarian patients visited the hearing aid outpatient clinic of the Department of Otorhinolaryngology, National Center for Geriatrics and Gerontology, to be fitted with new hearing aids, and they were the subjects of the present study. The subjects were assessed to determine their scores on the HHIE (Hearing Handicap Inventory for the Elderly), whether they had purchased hearing aids or not, whether they had family members living with them or not, and their motivation level (whether they or their family members were willing to see the doctor or not). The clinical course in the purchase group was followed for two years after they purchased hearing aids (17 of the 32 patients [53.1%] purchased hearing aids). The 17 patients who purchased hearing aids showed significantly greater compliance with hearing aid use and greater willingness to see the doctor than the 15 patients who did not purchase hearing aids (p=0.046, p=0.031). In the 14 patients who could be assessed by the HHIE before and after they purchased hearing aids, there was significant improvement in the total HHIE score, and in the scores on the social and emotional subscales after the start of hearing aid use as compared with those at the baseline (p=0.011, p=0.007, p=0.044). The results suggest that hearing aid fitting and continued use of hearing aids are feasible even for nonagenarians.

　 A comprehensive evaluation was performed of 9 patients with listening difficulties (LiD). The 9 patients underwent a basic hearing test, but showed no abnormalities and scored less than 109 points on the hearing difficulty check sheet. The patients were evaluated by Obuchi's auditory processing test (APT), clinical assessment for attention (CAT), and S-PA standard language-related examination of paired-associate learning, Rey with figure (ROCFT), repeat of the nonword of SALA, AQ Japanese version, CAARS Japanese version, and the Japanese version of SDS. In the APT, a large number of items were found to be impaired in the dichotic listening test, rapid speech listening test, listening in noise test, and listening in multiple voices test. In the CAT, there were cases in which all items were in the impaired range. The results of assessment by the Japanese version of the AQ, the ADHD index, and Japanese version of the SDS were in the impaired range in 1 case, 1 case and 3 cases, respectively. Furthermore, the more severe the hearing checklist symptoms, the stronger were the developmental and personality traits, and the likelihood of the patient's symptoms being more closely related to developmental and personality characteristics than to the APT or neuropsychological tests.