Japan is located in Northeast Asia or East Asia, positioned to the east of the Eurasian continent. It is surrounded by the Pacific Ocean, the Sea of Okhotsk, the Sea of Japan, and the East China Sea. The largest island, Honshu, approximately covering an area of 228,000 square kilometers, is the seventh largest island in the world. The total land area of the Japanese territory is approximately 378,000 square kilometers. Japan is a mountainous country, with two-thirds of its territory covered by forests. Most areas experience a temperate climate with four distinct seasons, although Okinawa in the south is subtropical, and Hokkaido in the north is subarctic¹.

According to the STATISTICAL HANDBOOK OF JAPAN 2023, published by the Ministry of Internal Affairs and Communications², Japan's total population in 2022 was 124.95 million. It ranks 11th worldwide and accounts for 1.6 percent of the world's total population. In 2022, the child population (0–14 years old) in Japan amounted to 14.50 million, accounting for 11.6 percent of the total population. Since 1997, the aged population (65 years and over) has surpassed the child population in terms of proportion of the total population. The working-age population (15-64 years old) accounted for 59.4 percent of the entire population.

Incidence and Prevalence of Hearing Loss

Newborn hearing screening has been implemented in Japan, and the results show that the incidence of bilateral newborn hearing loss is estimated to be approximately 0.1% in Japan. According to a questionnaire survey conducted by the Japanese Society of Otorhinolaryngology Head and Neck Surgery, the incidence of bilateral moderate to severe hearing loss was estimated to be 0.08% in newborns³. In addition, based on the results of newborn hearing screenings in Okayama Prefecture, bilateral hearing loss is identified in 0.1% of newborns⁴.

The prevalence of hearing loss in adults is more difficult to estimate than that in children. Nevertheless, according to a JapanTrak study (2018)⁵, 12.8% of the adult Japanese population (age>18) suffers from hearing loss. Namely, nearly one-eighth of adult Japanese answered yes when asked if they had hearing loss.

Age-related hearing loss (ARHL) is the leading cause of hearing loss in adults. Reported findings indicate that average hearing thresholds at 1000, 2000, and 4000 Hz in Japanese individuals aged 20–29 years are elevated compared to those aged 10–19 years. Furthermore, these thresholds tend to increase progressively with age from 10–19 years through 50–59 years⁶. Although the effects of age on hearing thresholds were observed as early as the 20s, the prevalence of hearing loss greatly increased after the age of 65 years when the threshold for hearing loss was defined to be >25 dB HL. The prevalence of hearing loss is 43.7%, 51.1%, 71.4%, and 84.3% in men aged 65–69, 70–74, 75–79, and over 80 years old, respectively. In women, the prevalence for the same age groups was 27.7%, 41.8%, 67.3%, and 73.3%, respectively⁷.

Information About Audiology

In Japan, there is no certification course for audiologists, and speech-language-hearing therapists play this role. Medical technologists are also engaged in hearing evaluations.

History of Speech-Language-Hearing Therapists

The need for a national qualification for speech-language-hearing therapists has been recognized since the mid-1960s: in 1971, the National Centre for Hearing and Speech Disorders (now the National Rehabilitation Centre for the Physically Disabled) established a training school for specialist personnel and began training speech-language-hearing therapists. Later, with the advent of a rapidly ageing society, the need for speech-language-hearing therapists to obtain national qualifications as soon as possible led to the enactment of the Speech-Language-hearing Therapists Act by the Diet in December 1997. The national licensing system was established by law in December 1997, and the first National License Examination for speech-language-hearing therapists was administered by the Ministry of Health, Labor, and Welfare in March 1999. The role of speech-language-hearing therapists is to provide assessments, treatment, and other necessary assistance to maximize clients' communication capacities. Services include not only hearing impairment but also speech impairment (aphasia, dysarthria, and cognitive dysfunction), language development delay, and voice and pronunciation disorders. In addition, they play specific roles in the assessment and rehabilitation of dysphagia.

Education

Speech-language-hearing therapists are qualified to apply for the qualification examination after completing three to four years of specialized education at universities or junior colleges designated by the Minister of Education, Culture, Sports, Science and Technology or at speech and language pathology training schools designated by the prefectural government after graduating from high school. Others may apply for the qualification examination by completing two years of training at a designated post-graduate special course or special training school after graduating from a four-year general university. Otherwise, those who have completed their studies in speech-language pathology abroad may qualify to undergo an examination if they are approved by the Minister of Health, Labor and Welfare.

The Japanese Association of Speech-Language-Hearing Therapists offers both basic and specialized post-graduate programs and seminars. After attending these programs and completing five years of post-graduate clinical experience, speech-language-hearing therapists are eligible to attend a six-day course for certified speech-language pathologists and become certified speech-language-hearing therapists. In addition, post-graduate training sessions are held by local JAS subcommittees and speech and language pathology training schools. Universities offer two-year master's and three-year doctoral degree programs, but the number of students enrolling in these programs is limited.

Audiology Practice

Audiology practice in Japan usually begins with a visit to an otorhinolaryngologist. Most speech-language-hearing therapists belong to large hospitals or clinics that specialize in speech-language pathology. Under the direction of an ENT doctor, they perform examinations, adjust hearing aids, and provide guidance on their use.

As part of the legal health check-up, infants, schoolchildren, workers, and older adults are required to undergo a medical examination that includes a brief hearing assessment.

In Japan, hearing aids are recommended to be purchased with the direction of a doctor and speech-language-hearing therapists, although some people purchase hearing aids without a diagnosis of hearing loss by a doctor or without the direction of a doctor or speech-language-hearing therapists, which has become problematic and needs to be corrected.

Services offered by Otolaryngologists

Otolaryngologists in Japan offer diverse ear-related services. Services include the diagnosis and management of acute and chronic pathologies, balance disorders, traumatic injuries, and congenital malformations, as well as the surgical treatment of chronic otitis media, external and middle ear anomalies, tumors, and hearing impairment. The most common surgical implants available are cochlear implants, followed by bone-anchored hearing aids and middle-ear implants. Patients also receive intra-tympanic steroid injections, mainly in the outpatient clinic, for the treatment of sudden sensorineural hearing loss.

Audiological Services

Audiological services provided by speech-language-hearing therapists in Japan are available in various settings, but they mainly work under the supervision of otolaryngologists. Speech-language-hearing therapists specializing in the audiological field at universities and primary hospitals are involved in hearing evaluations, hearing aid adjustments, language development evaluations, setting up cochlear implants and other auditory prostheses, newborn hearing screening, and student education. Many small- and medium-sized hospitals provide audiological services as well as speech, language, and swallowing services. Many speech-language-hearing therapists in small- and medium-sized hospitals do not specialize in audiology and often perform speech, language, and swallowing tasks in parallel with audiology. Outside hospitals, public health departments, schools, facilities for children with physical and communication handicaps, and medical equipment manufacturers may also provide hearing counseling, language development assessments, and education. Speech-language-hearing therapists can provide hearing and speech evaluation and rehabilitation services as a private practice, but few do so independently.

Professionals

Caption text
Professionals	Approximate Number	Ratio to the population
Speech-language-hearing therapists (SLHT)	39,896 (2023)¹	1:3160
SLHTs specialized in audiology	2,753¹	1:45770
Otolaryngologists	11,288 (2023)²	1:11440
Physicians	339,623 (2020)³	1:371
Medical Technologists	66,866 (2017)⁴	1:1880
Hearing Aid Specialists	4,683 (2023)⁵	1:54737

Professional and Regulatory Bodies

The Japanese Association of Speech-Language-Hearing Therapists (JAS) was founded in January 2000 to unite and represent nationally licensed speech-language-hearing therapists. JAS is a national professional and scientific association consisting of 21,081 (as of March 2023) nationally licensed members who work with and work for the millions of individuals with communication disorders and swallowing problems in Japan. Speech-language-hearing therapists provide assessment, treatment, and other necessary assistance to maximize clients' communication capacities. Services include not only hearing impairment but also speech impairment (aphasia, dysarthria, and cognitive dysfunction), language development delay, voice and pronunciation disorders, and dysphagia. A meeting of the Japanese Association of Speech-Language-Hearing Therapists is held once a year, with 2024 marking its 25th meeting.

Licensing

The national licensing system was established by law in December 1997, and the first national licensing examination for speech-language-hearing therapists was administered by the Ministry of Health, Labor and Welfare in March 1999. Approximately 1,600–2,000 people pass the exam each year, and the number of qualified applicants exceeded 30,000 in March 2018 and was approximately 40,000 in March 2023

Research in Audiology

Audiological research is active in Japan. Current research interest covers the entire scope of audiological practice, including the physiology and pathology of the auditory system, (re)habilitative devices, and (re)habilitation processes. The Congress of the Japan Audiological Society is held in Japan every year, and the one in 2023 was the 68th. Approximately 200 presentations are given each year. At the annual congress, the President and Directors of the Japan Audiological Society determine the themes each year, and special programs for these themes are arranged. Audiology Japan, a journal published by the Japan Audiological Society, has been in publication since 1958. This journal is published six times annually.

Audiology Charities

Challenges, Opportunities and Notes

Elucidation of the mechanisms of hearing and hearing disorders
Lack of awareness of the necessity for otorhinolaryngology consultation and hearing aids in people with hearing loss

Low rate of otorhinolaryngology consultation among patients who are aware of hearing loss
The utilization rate of hearing aids is low among patients who are aware of hearing loss.

Implementation rate of the newborn hearing screening test, which is more than 95%, should be 100%.
Prevention of noise-induced hearing loss

Hearing loss due to listening to music with earphones/headphones in young individuals
Thorough prevention of hearing loss in noisy working environments

Support policies for wearing hearing aids in hearing-impaired adult patients
Improvement of surgical and (re)habilitation methods for cochlear implantation

References

Ministry of Foreign Affairs: https://www.mofa.go.jp/territory/page1we_000006.html
Ministry of Internal Affairs and Communications. STATISTICAL HANDBOOK OF JAPAN 2023. https://www.stat.go.jp/english/data/handbook/index.html
The Infant and Child Committee Report of the Japanese Society of Otorhinolaryngology Head and Neck Surgery. Nippon Jibiinkoka Tokeibugeka Gakkai Kaiho Tokyo. 107: 529-546; 2004
Fukuda S, et al. Newborn Hearing Screening in Okayama Prefecture. the Japanese Journal of Voice and Speech Disorders 47: 379-383; 2006
Japan Hearing instruments manufacturers association. JapanTrak 2018. https://www.hear-it.org/japan-one-in-eight-say-they-have-a-hearing-loss.
Wasano K, et al. Patterns of hearing changes in women and men from denarians to nonagenarians. The Lancet Regional Health - Western Pacific. 9: 100131; 2021
Uchida Y, et al. Estimates of the size of the hearing-impaired elderly population in Japan and 10-year incidence of hearing loss by age, based on data from the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA). Japanese Journal of Geriatrics

		Contributor to the original text
Tatsuya Yamasoba