[Ross E. Mitchell, February 2005]
Can you tell me how many deaf people there are in the United States?
[Note: You will need to obtain the Adobe Acrobat Reader in order to view several of the documents mentioned below.]
This seemingly straightforward question does not have a simple answer. The answer is not simple because various definitions of deafness are used, depending on where you look for answers, each leading to a different estimate for the number of deaf people in the United States. Below, we discuss the various surveys used to estimate the size of the deaf population and report the answers they offer.
Please note that here at the Gallaudet Research Institute (GRI), we do not routinely collect data that would answer this question. The GRI manages the Annual Survey of Deaf and Hard of Hearing Children and Youth. The Annual Survey pertains only to those young people identified by their schools as receiving educational services related to their deafness. We do not manage surveys of the adult deaf and hard of hearing population.
A Brief Summary of Estimates for the Size of the Deaf Population
in the USA Based on Available Federal Data and Published Research:
About 2 to 4 of every 1,000 people in the United States are "functionally deaf," though more than half became deaf relatively late in life; fewer than 1 out of every 1,000 people in the United States became deaf before 18 years of age.
However, if people with a severe hearing impairment are included with those who are deaf, then the number is 4 to 10 times higher. That is, anywhere from 9 to 22 out of every 1,000 people have a severe hearing impairment or are deaf. Again, at least half of these people reported their hearing loss after 64 years of age.
Finally, if everyone who has any kind of "trouble" with their hearing is included then anywhere from 37 to 140 out of every 1,000 people in the United States have some kind of hearing loss, with a large share being at least 65 years old.
Where did we get the information for this summary?
SIPP and NHIS
Estimates of the number of deaf and hard of hearing persons in the United States are typically based on one of two national household surveys conducted by the federal government: the National Health Interview Survey (NHIS) or the Survey of Income and Program Participation (SIPP). We provide a brief overview, in round numbers, of what these and other surveys offer as partial answers to the question of how many deaf people there are in the United States.
SIPP. The SIPP is a multi-wave panel survey conducted annually by the U.S. Census Bureau. The estimates from this survey appear to effectively separate those who are deaf from those who are hard of hearing. From Wave 5 of the 2001 panel, this degree-of-hearing-loss distinction is based on an individual's or informant's response as to whether the individual should be identified as having "difficulty hearing what is said in a normal conversation with another person even when wearing your [his/her] hearing aid," with acceptable responses being "yes," "no," and "Person is deaf;" and if the answer is "yes," followed up by if the individual is "able to hear what is said in normal conversation at all." (for adults, Questions ADQ6 and ADQ7; for children, Questions CDQ11 and CDQ12)
We provide an independent analysis of SIPP public-use data files from the 2001 Panel, Wave 5. These data allow for national-level estimates of the prevalence of persons over five years of age in the United States who report some level of hearing impairment even with the use of a hearing aid. The advantage to this analysis is that we can classify persons with hearing impairment as either "functionally deaf" (namely, those identified as either unable to hear normal conversation at all, even with the use of a hearing aid, or as deaf) or hard of hearing.
Figure 1, below, summarizes the results from our analysis of the SIPP. The age-related pattern of reported hearing trouble makes it clear that most people with hearing impairment became deaf or hard of hearing due to age-related hearing loss – they had no "trouble" or "difficulty" hearing during childhood or early adulthood.
Figure 1. Percentage of persons who report difficulty hearing normal conversation by age group, United States, 2002
Across all age groups, in the United States, approximately 1,000,000 people (0.38% of the population, or 3.8 per 1,000) over 5 years of age are "functionally deaf;" more than half are over 65 years of age. About 8,000,000 people (3.7%) over 5 years of age are hard of hearing (that is, have some difficulty hearing normal conversation even with the use of a hearing aid). Again, more than half of those who are hard of hearing are over 65 years of age. We emphasize that these estimates are based upon self-reported (or informant-reported) hearing difficulty and not on independent audiometric measurements.
NHIS. The NHIS is conducted annually by National Center for Health Statistics (NCHS). Degree of hearing loss or deafness is determined by an individual's or informant's response to the question, "Which statement best describes your [child's] hearing (without a hearing aid): good, a little trouble, a lot of trouble, or deaf?" (for adults in 2003, Question ACN.420; for children in 2003, Question CHS.250)
But NHIS reports do not clearly distinguish those who are deaf from those who are hard of hearing. This is because all annually produced NHIS (Series 10) reports combine "a lot of trouble" and "deaf;" these categories are not reported separately. The reason for this combination is that there are too few persons identified as "deaf" in any given year to provide reliable estimates.
In order to report those with "a lot of trouble" hearing separately from those who are "deaf," we provide an independent analysis of NHIS public-use data files for the years 1997-2003. By combining multiple years in a single analysis, it is possible to dramatically improve the reliability of national-level estimates of the prevalence of persons in the United States who report some level of hearing impairment. That is, we can estimate the proportion of the population with a particular degree of hearing impairment during the time period from 1997-2003.
Figure 2, below, summarizes the results of this analysis of the 1997-2003 NHIS public-use data files. Just as noted above for the SIPP findings, there is a clear age-related pattern of reported hearing trouble because many respondents had "good" hearing during childhood or early adulthood.
Figure 2. Percentage of persons who report some level of hearing trouble by age group, United States, 1997-2003
Across all age groups, approximately 600,000 people in the United States (0.22% of the population, or 2.2 per 1,000) are "deaf;" more than half are over 65 years of age. About 6,000,000 people (2.2%) report having "a lot of trouble" hearing with, again, more than half over 65 years of age. Over 28,000,000 people (10%) report having "a little trouble" hearing with just less than a third over 65 years of age, but more than half over 45 years of age. Altogether, more than 35,000,000 people (13%) report some degree of hearing trouble. Again, we emphasize that these estimates are based upon self-reported (or informant-reported) hearing trouble and not on independent audiometric measurements.
If we were to compare the NHIS and SIPP results, it would not be a fair comparison. The NHIS responses are based upon hearing trouble without a hearing aid while SIPP responses are based upon hearing difficulty even with a hearing aid (note: not all persons with hearing difficulty wear a hearing aid, so persons who reported difficulty hearing may or may not use a hearing aid). Nonetheless, if a comparison must be made, only the responses for persons over 5 years of age should be considered. The only change to the "round numbers" resulting from ignoring responses for those under 6 years of age on the NHIS is that just less than 35,000,000 people over 5 years of age report some degree of hearing trouble without the use of a hearing aid. This hardly noteworthy change should not be too surprising since the prevalence of early childhood hearing impairment and deafness is low, so the number of persons to be subtracted from the overall total is small and has little effect on total population estimates.
NHANES. The National Health and Nutrition Examination Survey (NHANES) has been conducted four times (periodically, over a multi-year period each time, since 1971) by NCHS. Unlike any of the other federal surveys, NHANES has identified degree of hearing loss audiometrically (i.e., by a formal pure-tone-threshold hearing test using an audiometer rather than from responses to a self-reported hearing loss scale). Based on analysis of NHANES III data, as well as regular and supplemental NHIS data from the early 1990s, a research team sponsored by the Project HOPE Center for Health Affairs estimated that somewhere from 400,000 to 700,000 people have a severe or profound hearing loss (those likely to be deaf; about 0.19% to 0.34% of the population, or 2 to 3 per 1,000).
Please note that the pure-tone-threshold audiometric data from NHANES III were only for persons 6 to 19 years of age. The current NHANES is collecting pure-tone-threshold audiometric data only for persons 20 to 69 years of age. Estimates for a person's degree of hearing loss from recent NHANES is otherwise based upon the same self-reported "hearing trouble" scale used in the NHIS.
Census 2000. As it turns out, the decennial census is not a good source for deafness statistics. This is because the sensory disability question on the census form (Question 16) did not separate those who are deaf from those who are blind. The U.S. Census Bureau estimates that there are over 9,000,000 people with a severe sensory disability (3.62% of the population). This estimate is not a simple sum of all self-identified deaf and blind persons, however, because some persons may have identified with having "a severe vision or hearing impairment" instead. Somewhere between one-quarter and one-half of this group is likely to be persons with deafness or a severe hearing impairment (i.e., about 0.9% to 1.8% of the population, or 9 to 18 per 1,000). Note that about half of these people are over 65 years of age, and about one-tenth under 18 years of age.
Annual Report to Congress on the Implementation of the Individuals with Disabilities Education Act (IDEA Child Count). For children and youth 6 to 21 years of age, the IDEA Child Count prepared by the Office of Special Education Programs (OSEP) offers some information on the prevalence of significant hearing loss among schoolchildren. Over 70,000 children and youth were identified as receiving IDEA-related special education because the child had a "hearing impairment" of educational significance, which is 0.15% (1 to 2 per 1,000) of the total public K-12 school enrollment. However, the Annual Survey informs us that there are many hard of hearing children receiving special education (about 58%), not just deaf children (about 42%), which would lead to estimates that fewer than 1 of every 1,000 public schoolchildren is a deaf child receiving special education while about 1 of every 1,000 is a hard of hearing child in special education.
How many people are "Deaf" and how many use ASL?
For the last several years, many writers have distinguished between those who are deaf and those who are "Deaf." The capitalization indicates sociolinguistic affiliation in addition to audiological distinction. None of the above federal survey activity inquires about special language use or social identification among those who are deaf (or hard of hearing). That is, there are no questions about American Sign Language (ASL) or any other signed language use on federal surveys. The only study that helps to answer this question was done over 30 years ago (before IDEA, ADA, Section 504 of the Rehabilitation Act, etc.). Based upon this old survey (part of a project known as the National Census of the Deaf Population [NCDP]), we first estimated there may have been 500,000 persons who signed at home in 1972 (about 0.24% of the population), only slightly over half of whom were deaf (280,000 or 0.14% of the population). In other words, in 1972, a little more than 1 of every 1,000 people in the United States was a deaf person who reported s/he was a "good" signer.
However, if we were to take a more liberal view of who would have counted as an ASL user among those responding to the NCDP then, of course, our numerical estimates would be higher. That is, including those NCDP respondents who identified themselves as “fair” or “poor” signers results in an estimated 642,000 persons who signed at home in 1972, more than half of whom were deaf (375,000 or 0.19% of the population). These and other estimates are discussed at greater length elsewhere:
Mitchell, Ross E., Travas A. Young, Bellamie Bachleda, and Michael A. Karchmer. 2006, in press. "How Many People Use ASL in the United States? Why Estimates Need Updating." Sign Language Studies, Vol. 6, No. 3.
There is really no way to know if the proportion of deaf signers in 1972 has stayed close to the same over the last few decades. Certainly, the medical, legal, social, economic, and educational circumstances for Americans who are deaf have changed significantly since the NCDP. Nonetheless, if the proportion of deaf signers has remained roughly the same, then they would continue to number in the hundreds of thousands today (360,000 to 517,000). Please keep in mind that this final estimate is just that, an estimate (and a very rough one at that), and is not based on any new data.
Additional sources and links:
More detailed or sophisticated analyses of the total deaf and hard of hearing population in the United States, as determined using NCHS measures, would require obtaining the NHIS and NHANES data files or await future NCHS Series 10 and NCHS Series 11 reports, respectively. Similarly, access to analyses using Census measures requires obtaining SIPP data files or awaiting future SIPP P-70 Reports.
For national estimates from 1990-91, which provide a careful breakdown by level of "hearing trouble" and other demographic characteristics, please refer to the GRI's Demographic Aspects of Hearing Impairment: Questions and Answers (Third Edition), 1994.
As noted above, the Project HOPE Center for Health Affairs published a more narrowly focused analysis. "The Severely to Profoundly Hearing Impaired Population in the United States: Prevalence and Demographics" draws from multiple national surveys during the early- to mid-1990s.
According to this review and reanalysis of national data (1990 and 1991 NHIS Hearing Supplement, 1994 and 1995 NHIS, and NHANES III), an estimated one-half million Americans have severe to profound hearing loss (those most likely to be called deaf), 8% of whom are children (3-17 years) and 54% of whom are adults 65 years of age or older.
Citation: Blanchfield, B. B., Dunbar, J., Feldman, J. J., & Gardner, E. N. (1999, August). The severely to profoundly hearing impaired population in the United States: Prevalence and demographics. Bethesda, MD: Project HOPE Center for Health Affairs. (A shorter Policy Analysis Brief [Series H, Volume1, Number 1, October 1999] was published as well.)
For current summary information about a large sample of deaf and hard of hearing children identified for educational services, see the Annual Survey: 2002-2003 Regional and National Summary. Additional inquiries about current analysis of the Annual Survey should be directed to Dr. Sen Qi.
Neither we at the GRI nor those at the Census Bureau, NCHS, or OSEP can readily answer questions for which no reports have been prepared. Also, please note that state- and local-level data on deaf and hard of hearing persons are rarely available. We are not able to provide any information on obtaining such data, however, we recommend contacting state, county, or city public health departments to determine if such data are available.
Ross E. Mitchell, 15 February 2005
[Last modified: 2011.12.05 16:50:34. by Kevin Cole]