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Understanding the scale and impact of hearing loss is essential for developing effective assistive technologies. This section outlines the global scope and significance of hearing loss and deafness.

  1. 1.5 billion people experience hearing loss globally.
  2. 430 million people require rehabilitation for disabling hearing loss.
  3. 70 million people are considered deaf.
  4. 12[1]-24[2]-25[3] million people primarily use sign languages.

Hearing Loss[4] ​

The World Health Organization (WHO) estimates that globally, 1.5 billion people live with some degree of hearing loss, a number expected to rise to 2.5 billion by 2050. This increase is driven by factors such as population aging, unsafe listening habits, limited access to care, preventable causes going untreated, and insufficient early screening. Of these, 430 million people experience disabling hearing loss, requiring rehabilitation to improve quality of life. By 2050, this number is projected to grow to 700 million.

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The WHO estimates that unaddressed hearing loss poses an annual global cost of US$ 980 billion. This figure includes health sector costs (excluding hearing devices), educational support, loss of productivity, and broader societal costs.

These impairments are defined per ear, as follows[5]:

GradeHearing Loss (dB)Description
0: No impairment0–25 dBNormal hearing or no significant hearing difficulty.
1: Slight impairment26–40 dBAble to hear and repeat words spoken in normal voice at 1 meter; may have difficulty in noisy settings.
2: Moderate impairment41–60 dBAble to hear and repeat words spoken in raised voice at 1 meter; struggles with conversation.
3: Severe impairment61–80 dBAble to hear some words when shouted directly into the ear; significant communication challenges.
4: Profound impairment including deafness>80 dBUnable to hear and understand even when shouted directly into the ear; often relies on visual communication methods.

Deafness[6] ​

Among those with disabling hearing loss, the World Federation of the Deaf (WFD) estimates there are approximately 70 million deaf people worldwide. This community spans over 200 sign languages (or over 300[7]), underlining the linguistic diversity of deaf populations.

Reliable data on how many people use sign languages is difficult to establish, as estimates vary depending on definitions, data sources, and who is included (e.g., native users vs. broader communities of signers) The European Centre for Modern Languages[1:1] estimates that on average, deaf sign language users make up about 0.16% of the whole population in any given country, amounting to 12 million people worldwide. According to Ethnologue (via Derivation[2:1]), there are 24 million native sign language users worldwide, and according to a conglomeration of sources[3:1], the number signers for the top 100 used sign languages is 25 million.

Sign Language Interpreters ​

Sign language interpreters are in short supply globally, limiting access to essential services for deaf communities. In Israel, a survey found that 67% of interpreters decline one-hour assignments[8], often due to low compensation and inefficient scheduling. This reflects how availability alone doesn’t guarantee accessibility.

We list the number of interpreters in various countries below. For all countries in Europe, visit https://www.eud.eu/member-countries/.

CountryPopulationHoH PopulationDeaf PopulationInterpretersDeaf Interpreters
United States331 million (2023)11[9]-12[10] million1 million[11]10,385[12]
India1.4 billion (2023)2 million[13]300[13:1]
Germany83 million[14]200,000[15][16]750[15:1]26-30[16:1]
Switzerland8.7 million[14:1]800,000[17]10,000[17:1][16:2][18]63 Swiss-German, 32 Swiss-French, 8 Swiss-Italian[18:1](1-5 Swiss-German, 1-5 Swiss-Italian)[16:3]
Israel9.7 million (2023)55,700[19]10,000[20]147[21]-200[8:1]
The United Kingdom77,000[16:4]16-20[16:5]
Slovenia1016[22]61[22:1]2-5[16:6]
Spain100,000[23]667[23:1]<15[16:7]
Austria8,000 – 10,000[16:8][24]150[24:1]5[16:9]
Belgium6,500[25] - 9,000[16:10]165[25:1](5-10 Flanders, 16-26 Wallonia)[16:11]

Hearing Sign Language Users ​

Not all sign language users are deaf. A significant number of hearing individuals use sign languages fluently or regularly, contributing to higher user estimates in some sources.

These include:

  • Children of Deaf Adults (CODAs) hearing children who grow up using sign language as a primary means of communication. [26]
  • Sign language interpreters and trainees who acquire advanced signing skills through professional training.
  • Educators, social workers, and healthcare providers who use sign language to communicate with deaf clients or students.
  • Hearing individuals learning sign language for academic, cultural, or personal reasons.

Sources such as Ethnologue[2:2] report up to 24 million native sign language users, a figure that may reflect both deaf and hearing signers, depending on the definition used. This broader inclusion helps explain why estimates vary between 12 and 25 million sign language users worldwide. Understanding who is included in these figures is important when interpreting population data, especially for developing inclusive technologies and services.

  1. European Centre for Modern Languages. 2024. Facts about sign language. ↩︎ ↩︎

  2. Derivation. 2022. International Day of Sign Languages 2022. ↩︎ ↩︎ ↩︎

  3. Shester Gueuwou. 2023. Sign Language Info ↩︎ ↩︎

  4. World Health Organization. 2021. Fact Sheet: Deafness and Hearing Loss. ↩︎

  5. World Health Organization. 1991. Report of the informal working group on prevention of deafness and hearing impairment programme planning. ↩︎

  6. World Federation of the Deaf. 2024. Our Work. ↩︎

  7. United Nations. 2024. International Day of Sign Languages. ↩︎

  8. Omer Sharvit. 2022. מחסור חמור במתורגמנים לשפת הסימנים. ↩︎ ↩︎

  9. Disability Statistics. 2022. Disability Statistics. ↩︎

  10. Center for Research on Disability. 2023. Build Your Own Statistics. ↩︎

  11. Mitchell, Ross E. 2005. How many deaf people are there in the United States? Estimates from the Survey of Income and Program Participation. ↩︎

  12. Registry of Interpreters for the Deaf. 2024. Publications. ↩︎

  13. World Federation of the Deaf. 2024. News: Special Interest Groups. ↩︎ ↩︎

  14. International Association of Conference Interpreters. 2024. The Swiss Interpreting Market. ↩︎ ↩︎

  15. European Union of the Deaf. 2024. Member Countries: Germany. ↩︎ ↩︎

  16. Danish Deaf Association. 2016. Deaf Interpreters in Europe. ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎

  17. Swissinfo. 2021. Positive signs: Swiss Deaf Federation marks 75 years of adversity. ↩︎ ↩︎

  18. European Union of the Deaf. 2024. Member Countries: Switzerland. ↩︎ ↩︎

  19. Central Bureau of Statistics, 2024. Data on People with Hearing Impairments in Israel on the Occasion of World Hearing Day 2024. ↩︎

  20. Meir et al. 2010. Emerging sign languages. ↩︎

  21. Malach Israel. 2024. רשימת מתורגמנים. ↩︎

  22. European Union of the Deaf. 2024. Member Countries: Slovenia. ↩︎ ↩︎

  23. European Union of the Deaf. 2024. Member Countries: Spain. ↩︎ ↩︎

  24. European Union of the Deaf. 2024. Member Countries: Austria. ↩︎ ↩︎

  25. European Union of the Deaf. 2024. Member Countries: Belgium. ↩︎ ↩︎

  26. Medical Life Sciences. 2025 [Children of Deaf Adults (CODA)](https://www.asha.org/public/hearing/Children-of-Deaf-Adults-CODA--Communication-Challenges/#:~:text=Children of deaf adults (CODA) refer to hearing children who,children ↩︎