March 2026 Hearing

Why Is My Child Failing Hearing Tests? Understanding Glue Ear and Grommets

The most likely cause is glue ear: a build-up of thick fluid behind the eardrum that muffles sound and causes temporary hearing loss. It is the single most common reason Australian children fail hearing screenings. If the fluid persists for more than three months, your child's GP may refer you to an ENT specialist to discuss grommets.

What Is Glue Ear?

Glue ear, known medically as otitis media with effusion (OME), occurs when the middle ear space behind the eardrum fills with thick, sticky fluid. Unlike an acute ear infection, glue ear is usually painless. The fluid prevents the eardrum and the tiny bones of the middle ear from vibrating properly, which reduces the amount of sound reaching the inner ear.

Glue ear is extremely common in young children. Studies suggest that most children will experience at least one episode before school age, and it is the leading cause of hearing difficulty in children aged two to seven. The condition is often picked up through school hearing screening programs or when parents notice their child is not responding to speech at normal volume.

Why Does Glue Ear Cause Hearing Loss?

Sound travels through the ear canal, vibrates the eardrum, and passes through three tiny bones (the ossicles) in the middle ear before reaching the inner ear. When the middle ear is filled with fluid, this chain of vibration is dampened. The result is conductive hearing loss: typically a 20 to 40 decibel reduction.

To put that in perspective, a 30 dB hearing loss means your child hears normal speech as though they are listening through a wall. At school, this can mean:

Difficulty following the teacher, especially in noisy classrooms
Asking for things to be repeated
Turning up the television
Speech and language delays, particularly in younger children
Behavioural changes or frustration from not being able to hear clearly

Because glue ear is painless, it can go unnoticed for months. This is why routine hearing checks in early childhood are so important.

What Causes Glue Ear?

The Eustachian tube connects the middle ear to the back of the nose and is responsible for draining fluid and equalising pressure. In young children, this tube is shorter, more horizontal, and more easily blocked: which is why children are far more susceptible to glue ear than adults.

Common contributing factors include:

Upper respiratory infections: colds and viruses cause inflammation that blocks the Eustachian tube
Enlarged adenoids: overgrown adenoids can physically obstruct the Eustachian tube opening
Allergies: allergic rhinitis can cause persistent Eustachian tube swelling
Passive smoke exposure: increases the risk and duration of middle ear fluid

When Are Grommets Recommended?

Not every child with glue ear needs grommets. In many cases, the fluid resolves on its own within three months. Current Australian guidelines generally recommend a period of watchful waiting before proceeding to surgery.

Your ENT surgeon will typically recommend grommets when:

Fluid has been present in both ears for three months or longer
There is documented hearing loss affecting speech, language development, or learning
The child is getting recurrent acute ear infections on top of the glue ear
The eardrum is retracting or showing early structural changes from prolonged negative pressure

The Grommet Procedure: What to Expect

Grommet insertion (myringotomy and ventilation tube insertion) is one of the most commonly performed paediatric surgical procedures in Australia. It is a brief operation performed under general anaesthesia, typically as a day case.

Here is what the procedure involves:

A tiny incision is made in the eardrum under a microscope
The thick fluid is suctioned out of the middle ear
A small ventilation tube (grommet) is placed into the eardrum to keep the middle ear aerated
If the adenoids are significantly enlarged, the surgeon may remove them at the same time to reduce recurrence

The entire procedure takes approximately 10 to 15 minutes per ear. Most children go home a few hours after surgery and can return to school the next day. Hearing improvement is usually immediate once the fluid is cleared.

At Central Sydney ENT, all six of our FRACS-qualified surgeons perform paediatric grommet insertions. Surgeons with a particular interest in paediatric ENT include Dr Alexander Zhang and Dr Arjuna Ananda.

Recovery and Follow-Up

Recovery from grommet surgery is straightforward. Key points for parents:

Same-day discharge. Most children leave hospital a few hours after the procedure.
Ear drops. Antibiotic ear drops are typically prescribed for five to seven days after surgery.
Water precautions. Surface swimming is generally fine. Diving should be avoided.
Follow-up. A review appointment is scheduled for 4 to 6 weeks post-surgery, and then every 6 months until the grommets fall out naturally.
Grommet lifespan. Standard grommets usually fall out on their own after 6 to 18 months. The eardrum heals over within a few weeks.

If your child has failed a hearing test or you are concerned about their hearing, ask your GP for a referral to Central Sydney ENT. We consult from seven locations across Sydney. Call (02) 9747 3199 to book.

Frequently Asked Questions

What causes glue ear in children? +

Glue ear is caused by thick, sticky fluid building up in the middle ear behind the eardrum. It often follows colds, ear infections, or allergies. Children are more prone because their Eustachian tubes are shorter and more horizontal, making it harder for fluid to drain properly. Enlarged adenoids can also block the Eustachian tube opening and contribute to persistent glue ear.

How long do grommets stay in a child's ear? +

Standard grommets typically stay in place for 6 to 18 months before falling out naturally as the eardrum heals. Longer-lasting T-tube grommets may be used for children with recurrent glue ear and can stay in for two to three years. Your ENT surgeon will recommend the appropriate type based on your child's history.

Can my child swim with grommets? +

Most ENT surgeons allow surface-level swimming and bathing without ear plugs for children with grommets. Diving and jumping into water should be avoided as water forced into the ear under pressure can enter through the grommet. Your surgeon will provide specific advice based on the type of grommet used.

Will my child need a general anaesthetic for grommets? +

Yes, grommet insertion in children is performed under a brief general anaesthetic. The procedure itself takes approximately 10 to 15 minutes. Most children go home the same day and can return to school and normal activities the following day.