Hearing problems

Hearing problems can develop after some types of cancer treatment. They can happen in the first 2 years after treatment or later on.

If you are experiencing hearing loss, it's important to talk to your healthcare team. Sometimes hearing loss can also be a sign of other problems, such as a tumour pressing against a structure that helps with hearing.

The ears are fully formed at birth, but hearing is a big part of speech and language development during the first 3 years of life when the brain is developing and maturing. Babies and children have a higher risk of developing hearing problems after cancer treatment. Late effects from some treatments can cause permanent and severe (profound) hearing loss, which can make it difficult for children to learn to talk.

How the ears work

The ears collect and process sound and send signals to the brain. They also help with balance. Each ear is made up of 3 main parts.

The outer ear includes the visible part of the ear, which collects sound. It also includes the ear canal, where wax is made. Earwax helps fight infections by collecting dirt to keep the ear canal clean.

The middle ear is made up of 3 tiny bones that form a chain connecting the eardrum to the inner ear. The eardrum separates the outer ear from the middle ear. The middle ear is normally filled with air. Sound waves are turned into vibrations as they move through the eardrum to the inner ear. The middle ear also contains the Eustachian tube. It lies in the skull between the nasal cavity and the inner ear. It connects to the upper part of the throat. The Eustachian tube balances the air pressure in the ear so that it is the same on both sides of the eardrum.

The inner ear has the cochlea, which is a small, curled tube that is filled with liquid and lined with tiny nerve hairs. When sound reaches the cochlea, the vibrations cause the hairs to move, creating nerve signals that are transmitted to the brain.

Diagram of the ear
Diagram of the ear

Causes

The following cancer treatments and other factors can cause hearing problems.

Chemotherapy

Platinum chemotherapy drugs, such as cisplatin and carboplatin, can damage the cochlea in the inner ear.

The risk of damage to the cochlea is greater with higher doses of chemotherapy. This damage may cause permanent hearing loss or changes in balance.

Some people can have severe hearing loss from certain chemotherapy drugs even when they are given at low doses, while other people don't have any hearing loss when the same drugs are given at higher doses. Researchers are trying to find out if genetics may be involved in how chemotherapy drugs can affect hearing.

Radiation therapy

Radiation therapy to the head, ear or brain can cause hearing problems. These problems often occur within 3 years after treatment and can worsen over time. People who receive a high dose of radiation to the cochlea or are younger than 4 years of age during treatment have a higher risk for hearing problems. The risk of hearing problems can also increase if platinum chemotherapy drugs are given along with radiation therapy.

Radiation to the ear can harden earwax, irritate tissues or cause swelling of the Eustachian tube so that fluid builds up in the inner ear. These problems may be temporary and can go away a few months after radiation therapy is finished.

High doses of radiation can cause more permanent hearing problems and hearing loss. These problems may develop if radiation changes the little bones inside the middle ear or causes problems with the Eustachian tube.

Surgery

Surgery involving the brain, ear or auditory nerve may cause hearing problems.

Certain medicines

Medicines that can cause hearing problems include:

  • antibiotics, such as erythromycin, neomycin, gentamicin, streptomycin or tobramycin
  • diuretics, such as furosemide (Lasix) or ethacrynic acid (Edecrin)

Other factors

The following can increase the risk for hearing problems:

  • being younger than 4 years old at the time of treatment
  • receiving both chemotherapy and radiation therapy
  • having hearing problems or a risk for them before cancer treatment
  • having a tumour, surgery or an infection in your brain, ear or auditory nerve can cause a buildup of fluid in the brain that can affect hearing

Types of hearing problems

Hearing problems that can develop after cancer treatment include hearing loss and ringing in the ears (tinnitus). Hearing loss can be mild, severe or somewhere in between. You may have hearing loss, tinnitus or both.

There are 2 main types of hearing loss:

Conductive hearing loss is caused by a blockage in the ear, such as a buildup of fluid or earwax, that prevents sound from travelling to the inner ear. Conductive hearing loss can be caused by problems with the Eustachian tube in the middle ear (called Eustachian tube dysfunction). If the tube doesn't open enough, the pressure in the middle ear changes. If the tube stays closed, fluid will fill the middle ear. Conductive hearing loss is often temporary and can be treated. Hearing usually returns to normal after the problem causing hearing loss is treated.

Sensorineural hearing loss is caused by damage to the tiny nerve hairs in the cochlea, to the auditory nerve in the inner ear or to the part of the brain that processes sound. This makes it difficult to hear soft sounds and to tell the difference between certain sounds. High-pitch sounds are usually the first to be affected by sensorineural hearing loss. Middle- and lower-pitch sounds can also be affected. Sensorineural hearing loss is usually permanent.

You can have both types of hearing loss. This is called mixed hearing loss.

Symptoms

Symptoms can vary depending on the type of hearing problem and include:

  • ringing or tinkling sounds in the ears
  • difficulty hearing or being easily distracted by background noise
  • missing parts of conversations or asking people to repeat things
  • not paying attention to sounds, such as voices or environmental noise
  • dizziness or vertigo
  • nausea or vomiting
  • difficulty with language development in young children
  • hard, crusty earwax

If symptoms get worse or don't go away, report them to your doctor or healthcare team without waiting for your next scheduled appointment.

Diagnosis

Before treatment for cancer begins, you may have tests to check your hearing. Tests are repeated during and after treatment to look for any changes. If hearing loss occurs, the dose of the chemotherapy drug or radiation may be lowered.

You may see an audiologist, otologist or both. An audiologist is a health professional who tests for hearing loss. An otologist is a medical doctor who treats people with ear problems.

Tests to check hearing may include:

Physical exam

Your doctor will look in the ears for signs of any problems, such as a blockage or infection. They may also test other parts of your nervous system, such as look at your eyes, check your reflexes and check your balance.

Hearing exam

A hearing exam is also called an audiogram. It may be done before treatment with drugs that may cause hearing problems or radiation to the head. This test provides doctors with a baseline that they can check your hearing against during and after treatment.

A hearing exam tests your ability to hear different sounds. Sounds vary based on the intensity (volume or loudness) and the pitch (speed of sound vibrations). Many different types of tests can be used to check hearing. Tests will be chosen based on your age and level of understanding.

Find out more about hearing exam.

Imaging tests

You may have imaging tests, such as a CT scan or an MRI, to look for any hearing problems.

Managing hearing problems

Hearing loss can affect your ability to communicate and carry out daily activities. If hearing loss develops, you will be evaluated by an audiologist, otologist or ENT (ear, nose and throat) doctor.

Treatments for hearing problems include:

  • removing earwax
  • antibiotics to treat any infection
  • surgery to insert a tube into the ear to drain fluid

Devices that can help with hearing problems include:

Hearing aids can be used to improve hearing. They are small devices that make sounds louder. You wear them in or behind your ear. There are different types available depending on your age, size and the extent of hearing loss.

Sound generators can be used to help tinnitus. They make sounds that cover up ringing so that it bothers you less. These can come as part of a hearing aid.

Auditory trainers (FM trainers) are devices that you wear in a room where you want to focus on what one person is saying (such as a classroom). The speaker wears a microphone and you wear a small device that helps you hear their voice.

Cochlear implants are electronic medical devices that a doctor implants into your inner ears during surgery. They bypass the damaged area of the ears to send signals to the auditory nerve, helping you hear.

Message relay services help people with hearing or speech problems make and receive phone calls. In a message relay service call, the relay operator communicates with one caller using text and the other by voice.

Other assisted devices are also available for people with hearing loss, including:

  • alarm clocks that vibrate
  • smoke detectors with flashing lights
  • closed captioning for TV

Other communication methods include speech reading (lip reading), sign language and cued speech.

Tips for communicating if you have hearing loss include:

  • Let people know you have problems hearing.
  • Ask the person talking to face you and get your attention before speaking.
  • Ask the person speaking to speak clearly and not too fast.
  • Have your conversation in a well-lit place.
  • Limit background noise or have your conversation in a quiet area.

Protecting your ears

Protect your hearing from further damage by quickly treating ear infections and any other ear problems. Avoid things that may further damage hearing. Avoid loud noises, such as vacuum cleaners, hair dryers, lawn mowers, yard trimmers, leaf blowers, motorcycles or 4-wheelers. Protect your ears during or try to avoid work that exposes you to loud noises, such as firefighting, construction, farming and airport work. Wear earplugs at concerts or avoid them. Do not use headphones at a high volume. If you can't avoid exposure, wear hearing protection such as earplugs or earmuffs and limit exposure as much as you can.

Follow-up

All people who are treated for cancer need regular follow-up. The healthcare team will develop a follow-up plan based on the type of cancer, how it was treated and your needs. Follow-up may include a physical exam and hearing tests.  

It is recommended that people who receive chemotherapy have a hearing test every 2 years after treatment is finished. People who receive radiation therapy should have a hearing test every 5 years.

For children, it is very important to schedule regular hearing tests before or when they are learning to talk. When children cannot hear or communicate with others, it can be harder for them to make friends, socialize and learn in school.

If there is any change in your hearing, you may need to have more frequent follow-up. People who receive radiation therapy have a greater risk for progressive hearing loss over time.

Expert review and references

  • American Cancer Society. Children Diagnosed With Cancer: Late Effects of Cancer Treatment. Atlanta, GA: American Cancer Society; 2012.
  • Late effects of childhood cancer. American Society of Clinical Oncology (ASCO). Cancer.Net. Alexandria, VA.: American Society of Clinical Oncology (ASCO); 2011.
  • Armenian SH, Meadows AT, Bhatia S . Late effects of childhood cancer and its treatment. Pizzo, P. A. & Poplack, D. G. (Eds.). Principles and Practice of Pediatric Oncology. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2011: 47: pp. 1368-1387.
  • Hobbie WL, Carlson C, Harvey J et al . Care of the survivor of childhood cancer. Baggott C, Fochtman D, Foley GV & Patterson Kelly, K (eds.). Nursing Care of Children and Adolescents with Cancer and Blood Disorders. 4th ed. APHON; 2011: 20: pp. 694-763.
  • Martini FH, Timmons MJ, Tallitsch RB. Human Anatomy. 7th ed. San Francisco: Pearson Benjamin Cummings; 2012.
  • National Cancer Institute. Late Effects of Treatment for Childhood Cancer (PDQ®) Patient Version. Bethesda, MD: National Cancer Institute; 2013.
  • Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. National Childhood Cancer Foundation & Children's Oncology Group. CureSearch. Bethesda, MD: 2008: http://www.survivorshipguidelines.org/.
  • Shad AT . Late effects of childhood cancer and treatment. eMedicine.Medscape.com. WebMD LLC; 2012.