Health technology: New cost-effective smartphone test for middle ear function

A newly developed smartphone attachment can be used to test the function of the middle ear – which plays a vital role in conducting sounds that we hear – reports a study published in Communications Medicine. The smartphone-based device costs $28 for the materials (excluding the price of the phone) compared to traditional devices that can cost up to $5,000 to purchase, meaning this may be particularly useful in low-income countries and rural areas where resources are limited.

Tympanometry is one of a number of tests used in the audiology clinic and tests middle ear function by measuring movement of the ear drum in response to changing air pressure. Accurately screening for middle ear disorders using tympanometry, along with other tools, can improve referrals to specialists and may reduce the possibility of serious complications that can occur if ear disorders are left untreated. Existing tympanometry equipment costs between $2,000 and $5,000 to purchase, limiting the availability of tympanometry and access to high quality hearing care in some parts of the world.

Justin Chan and colleagues developed a portable, lightweight and inexpensive tympanometry system that can be used as a smartphone attachment. The device forms a seal with the ear and varies air pressure within the middle ear to generate a reading (tympanogram) of ear drum mobility. The material cost of the attachment was $28.

The authors tested their device in 50 ears from a total of 28 paediatric patients, aged one to 20 years, attending an audiology clinic at Seattle Children’s Hospital (Seattle, US) who were assessed by five audiologists. They found 86% of the readings from the smartphone-based device were in agreement with readings from commercial tympanometers. The hardware and software designs of the new tool are made openly available to allow anyone to reproduce the device.

The authors conclude that their device has the potential to improve access to tympanometry, particularly in low- and middle-income countries where access to smartphones is increasing. Further studies will be needed to evaluate the device in larger populations, including adults and younger infants.