Hearing loss causes and symptoms

Hearing loss affects people of all ages and is more common than you might think. According to Statistics Canada, it is the third most common health problem in Canada. Untreated hearing loss can affect your ability to understand speech and can negatively impact your social and emotional well-being. Those who experience hearing loss often report a decrease in quality of life.

The good news? Hearing loss is well-understood, and it is important to know you are not alone and have ample resources available. By seeking information here, you’ve taken a first step in getting the information and help you need.

If you suspect hearing loss, you've come to right place! Learn the common causes and symptoms of hearing loss so you know when to seek help for you and your loved ones.

Hearing loss causes

There are many causes of hearing loss. Some causes are beyond your control, and other causes may be preventable:

• Exposure to prolonged or excessive loud noise
• Ear infections, trauma or ear disease
• Damage to the inner ear or tympanic membrane (eardrum) from contact with a foreign object (cotton swabs, bobby pins, etc.)
• Illness
• Certain medications (ototoxic drugs)
• Deterioration of hearing organ cells over time

Hearing loss symptoms

Hearing loss can present itself at any time and in many ways. It can be gradual or acute, but the symptoms are generally similar regardless of the cause.

Here a few signs that indicate you may have hearing loss:

• You have difficulty hearing people in noisy environments such as restaurants, shopping centers, sporting events, or movie theaters.
• You feel people seem to “mumble” quite frequently.
• You find it difficult to understand people over the phone.
• Family, friends or colleagues need to repeat themselves when speaking with you.
• You have trouble hearing people when you can’t see their faces or are in other rooms.
• You have difficulty following conversations.
• You have ringing, buzzing or hissing sounds in your ears.
• You are tired after attending social events.
• You avoid social situations due to difficult communication.
• You have misunderstood messages or mixed up verbal instructions.

Types of hearing loss

Sensorineural hearing loss

The first and most common type of hearing loss is sensorineural hearing loss, and it occurs when tiny hair cells within the inner ear (the cochlea) are damaged.

Sensorineural hearing loss is permanent, and in most cases, there are no medical or surgical treatment options. Hearing aids are the primary treatment for sensorineural hearing loss. In some situations, hearing aids are not beneficial for certain individuals with severe to profound sensorineural hearing loss. These people may benefit from cochlear implantation.

Sensorineural hearing loss is most commonly experienced as a sloping high-frequency hearing loss, typically associated with aging or noise exposure, and often both. High-frequency hearing loss may be difficult to notice because it occurs gradually over time. People with high-frequency sensorineural hearing loss often report they can hear people speaking, but not clearly and they are mumbling. These individuals are candidates for hearing aids. 

Conductive hearing loss

The second most common type of hearing loss is conductive hearing loss, and is a result from a problem in the outer or middle ear that prevents sound from entering the inner ear properly.

Conductive hearing loss can be caused by several different things. It can be due to earwax (cerumen) blocking the ear canal or some type of foreign object lodged in the ear canal. A very common cause of conductive hearing loss is fluid occupying the middle ear space. Fluid behind the eardrum is common when people experience cold and sinus symptoms and presents as a “blocked” feeling. This type of conductive loss can be temporary or chronic. It is also common for many children and even some adults to experience ear infections (otitis media).  Many times, a conductive hearing loss can be medically treated by a physician. We recommend a visit to your general physician or otolaryngologist (ENT).

Mixed hearing loss

The third most common type of hearing loss is mixed hearing loss. This type of hearing loss involves both sensorineural and conductive hearing loss components. Because mixed hearing loss can be more complicated to diagnose and treat, be sure to follow-up with your physician, otolaryngologist (ENT) or hearing care professional. Treatment options for mixed hearing loss will depend on whether the loss is more sensorineural or conductive in nature.

Degree of hearing loss

Hearing care professionals use the terms normal, mild, moderate, severe and profound to characterize the degree of hearing loss. Hearing loss is measured in decibels (dB), and these terms refer to an average of the decibel level of hearing loss present:

• Individuals with normal hearing (hearing threshold levels of approximately 20 dB) can hear most speech sounds in quiet and comfortable listening situations.
• Individuals with mild hearing loss (between 21 and 40 dB) may hear reasonably well in one-on-one conversation but will miss words and speech sounds when speech is quiet or when there is background noise present.
• Individuals with moderate hearing loss (between 41 and 70 dB) will miss many speech sounds. They may mishear parts of conversations or ask others to repeat themselves.
• Individuals with severe hearing loss (between 71 and 90 dB) will miss the majority of conversational speech and using telephones will be very difficult. People with severe hearing loss need hearing aids to perceive speech sounds at normal conversational levels.
• Individuals with profound hearing loss (91 dB or more) cannot hear speech sounds even when they are very loud. People with profound hearing loss need hearing aids or cochlear implants to perceive speech sounds. 

Untreated hearing loss makes it difficult to follow conversations and often leads to reduced contact with family, friends and colleagues, which can further turn into feelings of isolation and depression. Hearing is central to your health and quality of life. According to the Better Hearing Institute, people with untreated hearing loss often experience a decreased quality of life.

Taking care of your hearing is one of the important keys to maintaining an active intellectual and social life.

Myths and misconceptions about hearing loss

People who have no experience with hearing aids tend to have all sorts of misconceptions about them. Here are some of the most common:

• Myth: It’s unusual to have a hearing loss.
• Fact: It is not uncommon. In fact, 10 percent of all people and around 40 percent of people over 50 years old have a hearing loss.
   
• Myth: Hearing loss is for old people.
• Fact: Not true. 65 percent of people with hearing loss are younger than 65.
   
• Myth: Hearing aids are big and ugly.
• Fact: Today’s hearing aids are stylish, tiny and almost invisible when worn
   
• Myth: Hearing aids beep and squeal
• Fact: This may have been true many years ago. Today’s technologies ensure that these effects have been almost completely eliminated
   
• Myth: My hearing loss only affects my hearing.
• Fact: Not true. Having a hearing loss also affects your mental energy, ability to recall conversations and take part in social activities. It also affects your loved ones, family, friends, colleagues and anyone else who wants to communicate with you.

Noise-induced hearing loss

Noise-induced hearing loss (NIHL) is caused by damage to the hair cells that are found in your inner ear. Hair cells are tiny sensory cells that convert the sounds we hear (sound energy) into electrical signals that travel to the brain. Once they are damaged, these hair cells cannot grow back, causing permanent hearing loss.

Harmful sounds that can damage your hearing include, but are not limited to:

• A sudden intense sound such as an explosion 
• Continuous exposure to loud sounds over an extended period of time, such as sitting too close to a speaker at a concert
• Harmful sounds at work, at home and during recreational activities.

If you work in a hazardous noise environment, speak with health and safety personnel about noise exposure risk.

Noise-induced hearing loss can be caused by prolonged exposure to any loud noise over 85 dB.

• You have to shout over background noise to be heard.
• The noise is painful.
• The noise causes your ears to ring or buzz (tinnitus).
• You have decreased or "muffled" hearing for several hours after the exposure.

It is possible to prevent some causes of hearing loss. There are several precautions you can take to protect your hearing. If you work in a noisy place or participate in a noisy pastime and are concerned about your hearing, or if you suspect you may already have hearing loss, be sure to follow-up with your hearing care professional.