Smoking and Hearing Loss: One More Reason to Kick the Habit

Researchers have known the dangers of smoking tobacco for decades. Of course we know smoking cigarettes contributes to lung cancer, throat cancer, chronic bronchitis, emphysema, allergies and other breathing disorders. Yet, with all the solid, statistical data in place, one out of five Americans still puff away daily.

A published report on Audiology Online from Western Michigan University, authored by Dr. Bharti Katbamna, indicates a strong link between smoking and hearing loss – yet another reason to kick the habit.

Smoking Stats

While the number of teens who start smoking is actually down to approximately 10% according to the Center for Disease Control (CDC), within the overall population that number jumps to 20% – one in five. Chances are you’re a smoker or you know one – even the secret smoker who never smokes in public but still consumes 10 or more cigarettes a day, putting you (or your friend) at higher risk for a host of diseases and harmful conditions.

More number crunching? How about this for a startling statistic? Women smoke more than men, but not by much. That’s not unexpected. But, even though it’s well known that smoking during pregnancy is harmful to a developing fetus, an average of 11.4% of pregnant women smoke! And that number ranges from 6.3% to 26.2% based on state by state information. More than one-quarter of pregnant women smoke in some states. It’s almost too hard to believe, but it also indicates just how addictive tobacco is.

Many researchers compare tobacco addiction to heroin addiction in difficulty to quit. Ask any ex-smoker how hard it is to “stay clean.” There are lots of smokers today who have quit before – dozens of times, only to light up one day and fall back into their old, harmful ways.

“I smoke to relax.”

So relax. But as you do kick back to light up, consider this.

With each draw on that butt you inhale a variety of toxic chemicals. Formaldehyde, benzene, arsenic, vinyl chloride, ammonia and hydrogen cyanide among about 1 thousand other substances. Yumm. Or yuck! Feeling more relaxed?

Several studies have also demonstrated the dangers of second-hand smoke. A chemical called cotinine, when it appears in a non-smoker, is a clear indication of exposure to second-hand smoke. So, as you enjoy a smoke to calm your nerves, consider the damage you’re doing to your own body and to those loved ones around you.

Smoking and Hearing

Scientists have recognized the danger smoking presents to hearing for almost 40 years, though this danger hasn’t been studied to the extent other tobacco-related health risks have. Dr. Katbamna’s report indicates two distinct dangers to hearing associated with smoking.

 

 Break the habit to prevent hearing loss

The hearing process is extremely complex and so is the hearing mechanism. Most of us think of the ear as the pinna – the outer ear that we can see. But within our skulls is a complex collection of hearing parts. There’s the ear drum, the three smallest bones in the human body and a snail-shaped organ called the cochlea. The cochlea is a fluid filled organ lined with millions of hair-like projections waving in the cochlear fluid called hair-cells.

When a sound is produced – the doorbell rings – it activates a disturbance in the air in the form of sound waves. These sound waves are captured by the outer ear, directed down the ear canal where they vibrate the ear drum, also called the tympanic membrane. The ear drum vibrates in perfect sync with the frequency of the doorbell chime.

Next, these vibrations are passed through three small bones which then pass sound vibrations to the fluid-filled cochlea where the vibrations are picked up by the hair-cells which then transmit sound to the brain via electrical impulses along the auditory nerve.

Studies reveal that the dangerous chemicals in cigarette smoke affect can affect both the conductive mechanism in hearing (the middle ear vibrations) as well as the inner ear part of the hearing (the hair cells).

The affect smoking has on hearing appears to be correlated with the amount of cigarettes smoked. In a study conducted on Japanese office workers who smoke, the research showed “that as the number of cigarettes smoked per day and pack years of smoking increased, the risk for high-frequency hearing loss increased in a dose dependent manner…”

In other words, the more people smoked each day and the longer they smoked, the worse the hearing damage was – especially in the high frequency range – the high-pitched sounds like birds tweeting.

Cognitive Effects on Hearing

Unfortunately the negative effects of smoking do not stop within the inner ear but actually continue on into the brain.

Once sound is transmitted via the auditory nerves, the next process of “hearing” a sound requires our brain to first identify the source of the sound, interpret the sound and call on your brain’s memory to understand the sound being heard. And according to Dr. Katbamna’s report, findings from various studies “suggest that chronic nicotine use impairs cognitive auditory processing”. In other words smoking can negatively impair the brain’s ability to “hear” and interpret sounds.

Smoking, age and noise

Like anything in life, smoking can act “synergistically” with other hearing loss risk factors. For example, according to Dr. Katbamna a 2005 study “showed that smoking, age, and noise exposure together pose a greater risk for hearing loss than each factor alone. They showed that non-exposed nonsmokers in the 20-40 years age category were least likely to experience hearing loss, whereas smokers over 40 years with a history of noise exposure were most likely to show a hearing loss. They suggested that these synergistic effects were most consistent with biological interactions.”

In plain English, when you factor in smoking with hearing loss caused by exposure to loud noise and the age factor, well, you have a potent combination that may well lead to serious and irreversible hearing loss.

The damage

For all of you science and biology lovers you may be wondering – how exactly does the smoking cause hearing loss? What mechanism is it actually damaging? Well that is a good question.

According to Dr. Katbamna there is no direct evidence for the mechanisms of damage to the auditory system associated with cigarette smoke exposure”. However research does suggest there may be three different mechanisms that play a role in the development of hearing loss due to smoke exposure:

• The first mechanism may be related to hypoxia (lack of oxygen) – nicotine and carbon monoxide may actually deplete oxygen levels to the cochlea which is bathed in fluids and blood supply. Like any part of the body, if oxygen is depleted tissue damage can occur.
• The second mechanism is related to the interaction between nicotine and neurotransmitters in the auditory (hearing) nerve. Neurotransmitters essentially function as chemical messengers and if impaired they would no longer be able to properly tell the brain what is occurring along the hearing nerve.
• Lastly the third suspected mechanism is related to adolescent smoking. Studies have shown mechanisms within the hearing nerve are not fully developed until late adolescents; thus the hearing nerve pathways are particularly susceptible to damage, if environmental toxins like nicotine are introduced during the early adolescent years.

Planning on Kicking Butt?

Congratulations. You now have another reason to kick the habit, regardless of your age or how long you’ve been smoking. However, the American Lung Association and the entire professional medical community are pretty much in agreement that the best way to avoid health problems associated with tobacco use is to never start.

If you do smoke, quit and consider having your hearing tested to see if you have caused any damage to your hearing.

And if you’re an ex-smoker you deserve a pat on the back. You’ve done something very difficult for your own good health and for the health of those who live with you. However you may also want to consider having your hearing tested as damage may have already occurred.

If you don’t smoke don’t start.

Cheers to smoke free environments, healthy living and healthy hearing!

Source: http://www.healthyhearing.com/content/articles/Hearing-loss/Causes/42402-Smoking-and-hearing-loss