Key points
1.To overcome the disadvantages of the current hearing screening methods
2. To eliminate the disadvantages of the conventional FFVT
3.To invent a digital option to screen hearing loss
3. To test the accuracy and sensitivity of the mobile-app and FFVT
compared to PTA
4. To have more accessibility to screen hearing loss nationwide
Level of evidence : Level 2
Keywords : mobile apps; smartphone; audiometry; hearing loss;
hearing tests
INTRODUCTION
Hearing loss is a prevalent disease in the population. This disorder
does not only affect aging population but, also younger adults and
children. In children, this condition can implicate their normal speech
and language development. According to World Health Organization, about
466 million people have disabling hearing loss globally, which is about
5% of the world’s overall population. Among these vast numbers, 34
million are children. It is predicted that the number will escalate to
over 900 million people by 2050, in which one in ten people will have
the hearing loss disability.
There are various tests available to detect hearing loss in the clinical
settings, which can be either objective or subjective tests.. Tuning
fork, pure tone audiometry (PTA) and Barany box are the examples. The
commonest subjective test used is PTA. Hearing loss is tested with
audiometry by average of hearing thresholds at frequencies of 0·5 kHz, 1
kHz, 2 kHz, and 4 kHz while hearing loss of 35 dB and more are viewed as
disabling hearing losses.2 However, PTA is not a
practical solution for hearing screening in a large population as it
requires trained audiologists to conduct the test.3Moreover, not every healthcare facility own an audiology service as a
soundproof room with an audiometry are required.4,5
Free Field Voice Test (FFVT) or also known as whispered voice test is
another screening tool to detect hearing loss. This test can be used for
both children and adults as it uses a combination of numbers and
letters. In children, bi-syllabic words like cowboy and football are
often used.6 A study on FFVT reported that the test
had 90% test sensitivity in detecting hearing thresholds above 30 dB
HL, making it a suitable hearing screening tool.7General practitioners are often recommended to use FFVT to screen
hearing among the elderly. Clinical guidelines are also formulated by
various national health board to make hearing impairment as part of the
health screening.8 However, FFVT have been criticized
as there is no standardization of sound levels of speech among the
examiners. There is also a significant difference in the sound levels of
the examiners tested in different occasions, especially during a
whisper.6
With usage of mobile phones being an integral part of our daily lives,
many health-related apps are easily accessible now. Hearing assessments
can also be conducted via mobile phones which are portable,
cost-effective and accessible especially in resource-limited
settings.5 There is a growing interest in establishing
more of such digital services such as smartphone-enabled otoscope and
noise level detectors.9 In a recent systematic review
published, the validation of smartphone apps in supporting and
controlling tinnitus symptoms was reported. One of the relief therapies
analyzed is the mobile phone-based Cognitive Behavioural Therapy (CBT)
which proved to be beneficial to patients with tinnitus, which
frequently accompanies hearing loss.10
Our aim is to create a cost-effective, digital tool to screen hearing.
Thus, we have designed an app using Flutter-Dart language, which is a
programming tool used to create cross- platform mobile applications.
Mobile apps can be used to mimic the findings of FFVT and is dubbed by
the authors as the free field click test (FFCT). It is named as such as
it employs broad-band clicks to elicit a clinical response. There is
very little information in the literature about the validity of digital
hand-held devices on the detection of hearing loss. This study will
demonstrate on how a low-cost software can be developed and used to
detect hearing loss in the general population in the future.
MATERIALS & METHODS
Study Population
This study was conducted at a sound-proof room in ORL clinic in[removed for blind peer review] from December till March
2020. A total of 50 patients from the age of 18 until 80 years old with
primary complaint of hearing loss were recruited. These patients were
then randomly assigned into two groups; FFVT and FFCT which were then
compared with the gold standard of PTA. Patients whom were less than 18
and more than 80 years old with hearing loss and pregnant ladies were
excluded from this study. Patients with less than one year duration of
post-traumatic and post-operative hearing loss were also excluded.
Study design