Search for how many people use American Sign Language and you will meet the same figure everywhere: 500,000. It appears in news coverage, on advocacy sites, in marketing copy, and in more than a few grant proposals.
We went looking for the primary source. What we found is a good lesson in how statistics take on a life of their own.
Where the number actually comes from
The trail leads to the 1974 National Census of the Deaf Population by Schein and Delk, whose data describe the year 1972. The figure then travelled through 1974 Senate testimony on the Bilingual Courts Act and into general circulation, where it has remained ever since.
In 2006, researchers at Gallaudet University went back and examined it directly. Mitchell, Young, Bachleda and Karchmer published How Many People Use ASL in the United States? Why Estimates Need Updating in Sign Language Studies.1 Their conclusions are worth quoting carefully.
Schein and Delk, they found, "provided evidence that there may have been as many as 500,000 people, regardless of hearing status, who signed at home in 1972." The Gallaudet team's own calculation put the ceiling at "not more than 408,000 people who were 'good signers' in the home in 1972."
And then the line that matters most: "There has been neither subsequent research to update these estimates."
It is presented as a current number, but it describes 1972, more than fifty years ago. And it is presented as a count of Deaf people, but it counted everyone signing at home regardless of hearing status, which includes hearing family members, children of Deaf adults, and hearing signers.
Why nobody has a better number
The obvious question is why the US Census cannot simply answer this. The answer is a genuinely remarkable piece of administrative invisibility.
The Census language question asks what language a person speaks at home. Signed languages do not fit the question as written. Worse, when people wrote in ASL anyway, the Bureau historically coded those responses as English during processing. As the Gallaudet paper puts it, data on reported ASL use "are never encoded in the computerized files and, as a consequence, do not appear in U.S. Census reports."1
A language used by hundreds of thousands of Americans has been systematically processed out of the national statistical record. You cannot count what your instrument is not built to see.
What we can say with confidence
Several adjacent figures are properly sourced and current.
About 11 million Americans, roughly 3.6% of the population, considered themselves deaf or reported serious difficulty hearing in the 2021 American Community Survey.2 That is a population figure, not an ASL figure, and the two should not be conflated. Not every deaf or hard of hearing person signs, and many ASL users are hearing.
An earlier and narrower estimate from Mitchell using Survey of Income and Program Participation data put the functionally deaf population at around one million, alongside nearly ten million hard of hearing people, and noted that over half of that population is 65 or older.3
On the learning side the data is clean. Roughly 107,900 students were enrolled in ASL courses in US higher education in fall 2021, making ASL the third most studied language other than English in American colleges, according to the Modern Language Association's enrollment survey.4 That figure is about course enrollments rather than fluent users, but it says something real about ASL's standing.
Globally, the World Federation of the Deaf estimates that more than 70 million deaf people belong to signing Deaf communities and that there are 200 or more national sign languages, of which only about 40% are legally recognised.5 The WFD is explicit that there is no official count, and these are institutional estimates rather than published research findings, so they should be attributed rather than presented as hard data.
Why we are writing this
It would be easy for an organisation like ours to simply repeat the biggest available number. Bigger numbers make for better fundraising copy.
We would rather be the organisation a funder can check. If a foundation officer traces one of our citations and finds a 1972 survey being passed off as current data, we have not just lost that grant, we have given them a reason to doubt everything else we said. Precision is not pedantry when your credibility is the asset.
It is also worth naming what the missing data means. The absence of a current, reliable count of ASL users is not a neutral gap. It reflects decades of a language being treated as outside the categories that count. Any serious answer to "how many people use ASL" has to start by admitting that America has never properly asked.
Nobody knows how many people use ASL in the United States today. The commonly cited 500,000 describes signing at home in 1972 across both deaf and hearing people, and has never been updated. About 11 million Americans are deaf or have serious difficulty hearing. ASL is among the most studied languages in US higher education. A properly designed national count is overdue.
What is not in doubt is the experience underneath the statistics. Whatever the exact figure, there are hundreds of thousands of people whose primary language is not shared by almost anyone they will meet today. That is the problem we are building to solve, and it does not require a precise headcount to be worth solving.
Frequently asked questions
How many people use American Sign Language in the United States?
There is no reliable current figure. The widely cited 500,000 comes from a survey describing 1972, counted both deaf and hearing people signing at home, and has never been updated. About 11 million Americans are deaf or have serious difficulty hearing, though not all of them sign.
Why does the US Census not count ASL users?
The Census language question asks which language a person speaks at home, which does not fit signed languages. Historically, when respondents wrote in ASL, the Bureau coded those answers as English during processing, so ASL use does not appear in Census reports.
Is ASL a widely studied language?
Yes. Around 107,900 students were enrolled in ASL courses in US higher education in fall 2021, making it the third most studied language other than English in American colleges according to the Modern Language Association.
How many sign languages are there in the world?
The World Federation of the Deaf estimates there are 200 or more national sign languages, of which only about 40% are legally recognised. The WFD notes there is no official count.
Sources
- Mitchell, Young, Bachleda and Karchmer, "How Many People Use ASL in the United States? Why Estimates Need Updating," Sign Language Studies 6(3), 2006. Gallaudet University summary. https://gallaudet.edu/wp-content/uploads/gcloud/gal-media/Documents/Research-Support-and-International-Affairs/ASL_Users.pdf
- National Deaf Center knowledge base, "How many deaf people live in the United States," citing 2021 American Community Survey. https://help.nationaldeafcenter.org/article/51-how-many-deaf-people-live-in-the-united-states
- Mitchell, "How Many Deaf People Are There in the United States?", Journal of Deaf Studies and Deaf Education, 2006. https://pubmed.ncbi.nlm.nih.gov/16177267/
- Modern Language Association, Enrollments in Languages Other Than English in United States Institutions of Higher Education, released November 2023 covering fall 2021. https://www.mla.org/Resources/Guidelines-and-Data/Reports-and-Professional-Guidelines/Enrollments-in-Languages-Other-Than-English-in-United-States-Institutions-of-Higher-Education
- World Federation of the Deaf, Frequently Asked Questions. https://wfdeaf.org/contact/faqs/
- Rocky Mountain ADA Center, "The US Census and American Sign Language." https://rockymountainada.org/news/blog/us-census-and-american-sign-language
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