Early identification is the first step in addressing hearing loss. Since hearing loss is invisible, it often remains undetected. In the cases of infants and older adults, this
can have negative consequences on rehabilitation outcomes and cognition. For this reason, it is important to establish special measures to screen for hearing loss at
different stages across the life course, targeting those most likely at risk. As shown in Figure 2.3, those targeted include:
• newborns and infants;
• children, especially in pre-school and school settings;
• adults, especially older adults; and
• all who are at a higher risk of hearing loss across the life course, due to exposure
to noise, ototoxic chemicals and ototoxic medicines.

Technological development and research has made it possible to undertake such
screening, as detailed below.

2.3.1 IDENTIFICATION IN NEWBORNS

Given the important role of hearing in a child’s development and learning, it is
essential to address hearing loss at the earliest time possible (100, 101). Early
identification in newborns is made possible through screening.
THE IMPORTANCE OF SCREENING PROTOCOLS IN NEWBORNS
Hearing screening in newborns, when followed by prompt and appropriate
interventions, is effective in ensuring that those born with significant permanent
hearing loss do not experience the associated adverse impacts (102–108). Screening
generally follows one of two approaches: (i) universal screening, which covers all
infants; or (ii) “at-risk” screening, which targets the 8–10% of newborns at risk of
permanent hearing loss (109); when neither strategy is feasible, screening can
also be opportunistic (for example when a parent suspects hearing loss and takes
their child to be screened). “At-risk” screening typically includes infants who have
an identifiable risk factor for hearing loss. However, since only around 50–60% of
infants with permanent hearing loss show risk indicators (109), an unacceptably high
proportion can be missed through this selective strategy; thus wherever possible,
a universal approach is preferred (110–112) (see Box 2.5).

AVAILABILITY OF TOOLS FOR EARLY IDENTIFICATION (114, 115)

Widespread hearing screening of newborns has been made possible by the
development of portable, objective automated devices. Universal screening uses
either automated transient-evoked otoacoustic emissions (TEOAEs), which assess
SECTION 2 SOLUTIONS ACROSS THE LIFE COURSE: HEARING LOSS CAN BE ADDRESSED 85
outer hair cell function; or automated auditory brain response (AABR) testing, which assesses
the integrity of the auditory neural pathway to the auditory brainstem (114). Such screening can
be undertaken as early as the first day of birth. Accurate diagnosis can also be established within
the first month of life by performing the Auditory Brainstem Response (ABR) testing or Auditory Stead
State Response (ASSR) measurements (116, 117) as recommended by the Joint Commission on Infant
Hearing Screening (118).
While screening in itself is an important part of an early intervention programme, it must be
accompanied by appropriate follow-up and rehabilitation (119, 120). There
is ample evidence to demonstrate that children benefit significantly when
newborn hearing screening is coupled with early intervention programmes (often
referred to as early hearing detection and intervention (EHDI) programmes), and
that effectiveness increases the earlier the child (and family) is identified and
rehabilitation starts (102–108, 121). An example of what is included in a high-quality
EHDI programme is provided in Box 2.6.

EFFECTIVENESS OF NEWBORN HEARING SCREENING PROGRAMMES
When followed by prompt and suitable rehabilitation, the screening of newborns
brings significant advantages in terms of reducing the age of diagnosis and
intervention, as well as improved language and cognitive development (100, 124–
127). These advantages translate into improved social and educational outcomes
for infants who receive timely and suitable care.
Cost–effectiveness of newborn hearing screening is
demonstrated in studies from high-income countries
such as Australia, Netherlands, the United Kingdom,
and the USA, as well as middle-income countries
such as China, India, Nigeria and Philippines (128). In
China, for example, a long-term cost benefit ratio of
1:7.52 was reported (129), and in India, a cost analysis
revealed life-time savings (including societal costs) of
over 500 000 International dollars per case identified
(130).

VALUE FOR MONEY!

WHO conservatively estimated a return on investment
from newborn hearing screening in a lower-middleand
a high-income setting. Results, based on actual
costs, estimated that in a lower-middle-income setting
(taken as an example) there would be a possible
return of 1.67 International dollars for every 1 dollar
invested in newborn hearing screening. With a highincome
country, this return was estimated to be
6.53 International dollars for every 1 dollar invested.
In addition, the lifetime value of DALYs averted in each
individual would be 21 266 International dollars, and
the net monetary benefit 1.21 dollars. In the case of a
high-income setting, the value of DALYs averted would
be 523 251 International dollars.

2.3.2 IDENTIFICATION IN PRE-SCHOOL CHILDREN AND IN SCHOOL SETTINGS

Although, screening in newborns has improved the ability to identify and address
congenital hearing loss, children who have experienced minimal hearing loss at
birth, and those whose hearing loss is progressive or develops later in childhood
(e.g. from middle ear disease), often remain unidentified and without care. Early
identification of these conditions, especially ear diseases in children, and connecting
them to care, is critical for the provision of effective hearing care.
SCREENING AS PART OF SCHOOL HEALTH INITIATIVES
Given that, worldwide, the vast majority of children go to school (135), school screening
represents a unique opportunity to conduct universal hearing screening. School
screening programmes can be a useful tool in mitigating the effect of unaddressed
hearing loss and ear diseases (136); and for educating children regarding practices
that help maintain their hearing trajectory (as part of overall health), such as safe
listening (see section 2.2.4).
Positive experiences with respect to the overall impact of school health programmes
have been reported by a number of international agencies such as WHO, UNICEF,
88 WORLD REPORT ON HEARING
UNESCO and the World Bank (137) which, together, have developed a partnership:
Focusing Resources on Effective School Health (FRESH). Given the importance of
hearing in education; the frequency of ear and hearing problems in school-age
children; and the need to inculcate safe listening behaviours at an early age, the
inclusion of ear and hearing care in school health services and initiatives is essential.
TOOLS AND TECHNOLOGY-BASED OPTIONS FOR SCREENING AND TESTING
Several tools are available for facilitating hearing screening in school settings.
Audiometric evaluation has been shown to be accurate in assessing hearing in
school-age children (138). However, the application of such screening is often
limited in low-resource settings or remote areas due to several factors including
the high cost of equipment; requirements for intensive training of screeners in
audiometric principles; overreferrals; lack of environmental noise monitoring; and
poor data capturing and management (139, 140). Other technology-based options
have recently emerged that have facilitated conduct of hearing screening in school
settings. These include tools such as:
• mobile-based software applications
• automated hearing screening
• boothless audiometry
• telemedicine options.
These options are described in more detail in section 2.4.4.
Besides hearing assessment, other tests commonly used in a school ear and hearing
screening service include:
i. Otoscopic examination:
This examination identifies common problems of the outer or middle ear. Besides
traditional otoscopic examination, other technology-based solutions, such as
smartphone-based otoscopy apps, are available (141, 142). Otoscopic examination
can also be supported by telemedicine options (142, 143).
ii. Tympanometry:
This assesses middle ear function and diagnoses nonsuppurative otitis media (138).
iii. Otoacoustic emission testing (OAE):
This testing is relevant mostly in situations where children are unable to follow
instructions, e.g. in pre-school-age children or children with special needs (144).
EFFECTIVENESS OF SCHOOL SCREENING PROGRAMMES
To ensure the effectiveness of school screening programmes it is important that
a referral system is in place and that children requiring further investigations and
management should have access to services (136, 145). It is essential to outline the
SECTION 2 SOLUTIONS ACROSS THE LIFE COURSE: HEARING LOSS CAN BE ADDRESSED 89
A child in South Africa
undergoes hearing
testing using automated
audiometry and noisecancelling
headphones
© Hear the World Foundation
care pathway and follow-up mechanisms at the time
of intervention planning so that full benefits can
be realized.
• Children with progressive hearing loss may pass
the newborn hearing screening, but later be
identified through pre-school or school-based
ear and hearing checks (132, 135). Systematic
screening in children, followed by appropriate care,
can lead to timely identification and remediation
of common ear diseases. Such programmes are
especially useful where prevalence of common
ear diseases and hearing loss is high.
• School hearing screening programmes
represent an opportunity to reduce the health
and economic burden of childhood hearing
loss. However, to date, economic analyses
performed on this topic are few in number
and have mixed conclusions. While, overall, the
studies have found school screening to be cost–
effective, substantial uncertainty exists due to
methodological differences; moreover, external
validity of the available data is limited (147–151).

Further research in this area is urgently needed to
create standards for cost evaluations and to develop
generalizable, region-specific estimates that can be
translated to countries considering implementing
school screening.

2.3.3 IDENTIFICATION IN OLDER ADULTS

Given the global demographic trends (153), the need for hearing care among the adult
population is likely to continue to increase in the coming decades (154). Global Burden
of Disease estimates suggest that over 65% of the global population above the age of
60 years experiences some degree of hearing loss. Despite the functional limitations
associated with hearing loss (155), adults typically wait as much as nine to ten years
before seeking any hearing care (156, 157). To address this gap, it is essential to provide
active screening services for older adults in an easy and accessible manner, followed
by suitable interventions. Such screening can be undertaken by health-care providers,
such as general practitioners, primary level doctors or health workers (156, 158).
To support this, the WHO guidelines for integrated care of older persons recommends
that screening, followed by the provision of hearing aids, should be offered to older
people (see Box 2.7).

EFFECTIVENESS OF HEARING SCREENING IN OLDER ADULTS
• In older adults, hearing screening, followed by prompt hearing aid provision, is
associated with significant improvements in hearing-related health outcomes
(155, 159, 160).
• Adult hearing screening and early intervention become even more relevant
given the links between hearing loss and dementia in older adults (161), and
that addressing hearing through these devices may have a positive influence on
an individual’s cognition.
• Hearing conservation programmes implemented for the reduction of noiseinduced
hearing loss in factories and military services have been shown to be
cost–effective (89, 162). Although the cost–effectiveness of hearing screening in
older adults has not been studied extensively, limited available literature describes
a positive improvement to the quality of life of older adults, as well as economic
gains to society (156, 163, 164).
VALUE FOR MONEY!
WHO made a conservative estimation of return on investment from hearing
screening for adults aged above 50 years. Results based on actual costs estimated
a possible return of 1.62 International dollars for every 1 dollar invested in hearing
screening among older adults in a high-income setting, and 0.28 International
dollars in a middle-income setting, taken as examples.
In addition, the lifetime value of DALYs averted for 10 000 individuals screened would
be 8 877 785 International dollars. In the case of a high-income setting, the value
of DALYs averted would be 788 604 dollars for a similar population. Further details
are provided in WEB ANNEX B.

2.3.4 IDENTIFICATION OF THOSE AT HIGHER RISK

Individuals and populations at a greater risk of hearing loss commonly include those:
• exposed to noise or ototoxic chemicals at the workplace; and
• receiving ototoxic medicines.
Targeted hearing surveillance is an integral part of occupational hearing
conservation programmes as well as ototoxicity prevention, as described earlier.
Such surveillance not only provides a means for early detection, but also serves as
an early warning. Preventive measures, if taken immediately upon identification, can
reduce progression of hearing loss in those exposed to ototoxic influences.
Using the tools and strategies outlined above, early diagnosis of hearing loss is
possible, even in resource-limited settings. Screening programmes targeting
different risk groups can ensure that all persons with hearing loss have the possibility
of being identified in time for them to benefit from rehabilitation services and avoid
SECTION 2 SOLUTIONS ACROSS THE LIFE COURSE: HEARING LOSS CAN BE ADDRESSED 93
the adverse impacts of hearing loss. For this reason, it is essential that all screening
services are supported by appropriate diagnostic follow-up and rehabilitation.
2.3.5 INNOVATIVE SCREENING SOLUTIONS ACROSS THE LIFE COURSE
Hearing screening can be undertaken either through conventional screening
audiometry or technology-based solutions tools (156, 165); screening is facilitated
by the development of mobile-based software applications (142, 166, 167) which
provide tools that are cost–effective and easy to use. The range of tools include:
AUTOMATED HEARING TESTING (142, 168–170)
This reduces the need for training as the technology used can be programmed to
provide the signal and analyse the individual’s response.
DIGITS-IN-NOISE TEST (171–173)
This is based on speech recognition in noise and provides a functional measure as
it relates to speech recognition abilities rather than pure tone averages. It is both
accurate and quick; and can be administered online, through mobile applications,
and in community settings (172, 174–177). Based on the validated South African
digits-in-noise test (“hearZa”) (177, 178), the World Health Organization has developed
and launched the free smartphone applications “hearWHO” and “hearWHOpro” that
can be used by individuals and health workers to check for hearing loss (Box 2.8).

Other technology-based solutions include:

BOOTHLESS AUDIOMETRY

This is a means of testing without the need for a sound booth. As an example,
audiometry can be done through the use of noise-cancellation headphones (140, 167,
168, 179), which provide an effective adjunct for audiological testing in community
settings, such as schools.

TELEMEDICINE SERVICES (139, 143, 180)

Telemedicine is the delivery of health-related services and information via
telecommunications technologies. Teleotology and teleaudiology use telemedicine
to provide otological and audiological services remotely. Audiological findings and
otoscopic images are transmitted, commonly over the internet, from the point of
contact with the individual to an expert at a remote location. The diagnosis (and
where mandated management options) can be then transmitted back to the
individual (181, 182). These offer a valid solution to the discrepancies apparent in
the need for health-related services and their limited availability.
Early diagnosis of hearing loss is possible using the tools and strategies outlined
above, even in resource-limited settings. Screening programmes targeting different
risk groups can ensure that all individuals with hearing loss have the possibility of
being identified in time for them to benefit from rehabilitation services and avoid
the adverse impacts of hearing loss. For this reason, it is essential that any screening
service be supported by appropriate diagnostic follow up and rehabilitation.