Assessment & Research

Failure to detect deaf-blindness in a population of people with intellectual disability.

Fellinger et al. (2009) · Journal of intellectual disability research : JIDR 2009
★ The Verdict

One quick sensory screen can reveal that one in five adults with ID is deaf-blind—most cases are new to the chart.

✓ Read this if BCBAs serving adults or teens with ID in residential, day-program, or clinic settings.
✗ Skip if Practitioners working solely with typically developing children or mild learning delays.

01Research in Context

01

What this study did

The team screened every adult with intellectual disability in one Dutch facility. They used quick otoacoustic and vision tests that take minutes.

Before the study, staff had only routine medical notes. No extra training was added.

02

What they found

Systematic screening pushed deaf-blindness findings from 3.6% to 21%. Hearing loss rose from 12.5% to 46%. Vision loss rose from 17% to 38%.

Most cases had been missed for years. The tests caught them in one visit.

03

How this fits with other research

Richman et al. (2001) saw the same high rates in Dutch homes years earlier. Their numbers warned the field, but action was rare.

Hild et al. (2008) mirrored the result at Special Olympics. One in four athletes failed the hearing check. Together the papers show the problem is global, not local.

Savvas et al. (2025) now gives you a finer tool. DPOAE growth functions keep the 98% hit rate even when clients cannot follow instructions.

Cramm et al. (2009) adds the cost of ignoring: vision loss alone cuts daily skills far beyond ID level. Screening is not just polite—it protects adaptive gains.

04

Why it matters

If you work with adults who have ID, treat sensory screening like taking blood pressure. Schedule it yearly. Use otoacoustic clicks and a near-card vision chart. When you catch deaf-blindness early, you remove a hidden barrier to learning, compliance, and rapport. One clear test can replace months of puzzling behavior.

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Add a two-minute otoacoustic emission check and a near-vision card to your intake packet—flag any fail for audiology or optometry.

02At a glance

Intervention
not applicable
Design
survey
Sample size
224
Population
intellectual disability
Finding
positive
Magnitude
large

03Original abstract

BACKGROUND: Early identification of deaf-blindness is essential to ensure appropriate management. Previous studies indicate that deaf-blindness is often missed. We aim to discover the extent to which deaf-blindness in people with intellectual disability (ID) is undiagnosed. METHOD: A survey was made of the 253 residents of an institute offering residential and occupational facilities for people with IDs. Data are included for the 224 individuals who were able to complete both auditory and visual assessments. Otoacoustic emissions were used to screen for hearing impairment; those who did not pass were assessed by behavioural audiometry. Visual acuity was assessed with one of the following: EH-Optotypes, LH-Optotypes, Teller Acuity Cards, Cardiff Acuity Cards or the Stycar Ball Vision Test. RESULTS: Prior to the study hearing impairment had been diagnosed in 12.5% of the 224 subjects, and visual impairment in 17%. Upon completion of the study these figures rose to 46% and 38.4% respectively. Deaf-blindness was diagnosed in 3.6% of the subjects before, and in 21.4% after, the study. Most (87.5%) of the deaf-blind individuals had profound ID. CONCLUSION: Deaf-blindness is most often not identified either by standard medical screening or by care staff. Individuals with this disability, however, require provision of special kinds of care. Four categories of deaf-blindness are proposed, according to the severity of sensory impairment in each modality. The tests used in this study are non-invasive and are appropriate for individuals with ID and children. Early and periodic screening for visual and hearing impairment in individuals with ID is recommended.

Journal of intellectual disability research : JIDR, 2009 · doi:10.1111/j.1365-2788.2009.01205.x