Introduction
Globally 6% of the population, or around 466 million people, suffer from disabling hearing loss (www.who.int/pbd/deafness/estimates/en/), and the majority reside in low- and middle-income countries. One barrier to tackling this large burden is the lack of specialist health workers to recognise and manage ear and hearing disorders.1
Fuelled by technological advances, there is growing interest in remote or non-expert diagnosis in ear and hearing care. However, studies to date have been limited, mostly focused on screening for hearing loss, without exploring additional symptoms or signs which may signify middle or external ear disorders. This is important: of those suffering disabling hearing loss, around half (200 million) are thought to be due to chronic suppurative otitis media (CSOM),2 where surgical intervention may be indicated.
Diagnosis of external and middle ear disorders is based on clinical history, including symptoms of otalgia, otorrhoea, and hearing loss, supplemented by otoscopy to visualise the ear canal and tympanic membrane. Diagnostic accuracy relates to expertise and experience of the assessor. Specialist assessment with appropriate tools (including a good quality otoscope) is the gold standard, but due to resource gaps in equipment and specialist health personnel, is not universally available.
We recognise three alternative strategies (Figure 1):