Frequently Asked Questions & Answers on Ear Protection

Sound originates when a body moves back and forth rapidly enough to send a travelling wave through the medium in which it is vibrating.

The transmitter of the sound, whether it is a voice or some other noise-making device, creates the sound by alternately compressing the air and then relaxing the compression.

A sound wave consists of regions of compression, in which the air molecules are close together and the pressure is relatively high, alternating with areas of rarefaction, where the molecules are farther apart and the pressure is lower.

The loudness of a sound is related to the amplitude of the sound wave – that is, to the pressure difference between a zone of compression and a zone of rarefaction.

The pitch of a sound is related to the frequency of the sound wave (usually expressed in cycles per second, or Hertz, Hz). In general, the greater the amplitude of a particular sound wave, the higher the pitch of the sound.

The human ear is capable of detecting sound waves with frequencies between about 20 and 20,000 cycles per second.

However, the ear is most sensitive to sound waves with sequences between 1000 and 4000 cycles per second.

Human speech, which ranges from 300 to 8000 Hz, sounds louder to most people than noises at very high or very low frequencies.

When hearing impairment begins, the high frequencies are often lost first, which is why people with hearing loss often have difficulty hearing the high pitched voices of women and children.

Intensity of sound is measured in decibels (dB).

The scale runs from the faintest sound the human ear can detect, which is labeled 0 dB, to over 180 dB, the noise at a rocket pad during launch.

Decibels are measured logarithmically.

This means that as decibel intensity increases by units of 1, each increase is 10 times the lower figure.

Thus, 20 decibels is 10 times the intensity of 10 decibels, and 50 decibels is 10,000 times as intense as 10 decibels.

When does noise become dangerous?

People differ in their sensitivity to noise.

As a general rule, noise may damage your hearing if you have to shout over background noise to make yourself heard, the noise hurts your ears, it makes your ears ring, or you are slightly deaf for several hours after exposure to the noise.

Sounds that are sufficiently loud to damage sensitive inner ear structures can produce hearing loss that is not reversible by any presently available medical or surgical treatment. Hearing impairment associated with noise exposure can occur at any age, and is often characterized by difficulty in understanding speech and the potentially troublesome symptom, tinnitus (ringing in the ear).

Very loud sounds of short duration, such as an explosion or gunfire, can produce immediate, severe, and permanent loss of hearing. Longer exposure to less intense but still hazardous sounds, commonly encountered in the workplace or in certain leisure time activities, produces a gradual toll on hearing sensitivity, initially without the victim’s awareness.

Can noise really hurt my ears?

Yes – noise can be dangerous.

If it is loud enough and last long enough, it can damage your hearing.

The damage caused by noise, called sensor neural hearing loss or nerve loss, can be caused by several factors other than noise, but noise induced hearing loss is different in one important way – it can be reduced or prevented altogether.

Can I 'TOUGHEN UP' my ears ?

NO, if you think you have grown used to a loud noise, it probably has damaged your ears and there is NO treatment – NO medicine – NO surgery, not even a hearing aid that truly corrects your hearing once it is damaged by noise.

How can I tell if a noise is dangerous?

People differ in their sensitivity to noise.

As a general rule, noise may damage your hearing if you have to shout over background noise to make yourself heard, the noise hurts your ears, it makes your ears ring, or you are slightly deaf for several hours after exposure to the noise.

Does the length of time I hear a noise have anything to do with the danger to my hearing?

It certainly does.

The longer you are exposed to a loud noise, the more damaging it may be. Also, the closer you are to the source of intense noise, the more damaging it is.

Can noise effect more than my hearing?

A ringing in the ears, called tinnitus, commonly occurs after noise exposure and it often becomes permanent.

Some people react to loud noise with anxiety and irritability, an increase in pulse rate and blood pressure, or an increase in stomach acid.

Very loud noise can reduce efficiency in performing difficult tasks by diverting attention from the job.

Who should wear hearing protectors?

If you must work in an excessively noisy environment (above 80dB), you should wear protectors.

You should also wear them when you are using power tools, noisy yard equipment, or firearms.

What are hearing protectors? How effective are they?

Hearing protection devices decrease the intensity of sound that reaches the eardrum.

They come in three forms: ear plugs, earmuffs and otoplastics.

EAR PLUGS

Ear plugs are small inserts that fit into the outer ear canal.

To be effective they must totally block the ear canal with an airtight seal. They are available in a variety of shapes and sizes to fit individual ear canals and can be custom made.

For people who have trouble keeping them in their ear, they can be fitted to a headband.

Ear plugs must be snugly sealed so the entire circumference of the ear canal is blocked.

An improperly fitted, dirty or worn-out plug may not seal, can irritate the ear canal and contribute to hearing damage.

EAR MUFFS

Ear muffs fit over the entire outer ear to form an air seal so the entire circumference of the ear canal is blocked and they are held in place by an adjustable band.

Ear muffs will not seal around eyeglasses or long hair and the adjustable headband tension must be sufficient to hold ear muffs firmly around the ears.

FLEXCOMFORT

Otoplastics are individual fitted ear inserts.

A sound channel is drilled in which an attenuation filter is fitted.

Depending on the application the appropriate filter is selected.

What does frequency have to do with hearing loss?

Frequency is measured in cycles per second, or Hertz (Hz).

The higher the pitch of the sound, the higher the frequency.

Young children, who generally have the best hearing, can often distinguish sounds from about 20 Hz, such as the lowest note on a large pipe organ, to 20,000 Hz such as the high shrill of a dog whistle that many people are unable to hear.

Human speech, which ranges from 300 to 8000 Hz, sounds louder to most people than noises at very high or low frequencies.

When hearing impairment begins, the high frequencies are often lost first, which is why people with hearing loss often have difficulty hearing the high pitched voices of women and children

Loss of high frequency hearing also can distort sound.

Hearing impaired people often have difficulty detecting differences between certain words that sound alike, especially words that contain S, F, SH, CH, H, or soft C, sounds, because the sound of these consonant is in a much higher frequency range than vowels and other consonants.

What about decibels?

Intensity of sound is measured in decibels (dB). the scale runs from the faintest sound the human ear can detect, which is labeled 0 dB, to over 180 dB, the noise at a rocket pad during launch.

Decibels are measured logarithmically.

This means that as decibel intensity increases by unit 1, each increase is 10 times the lower figure.

Thus, 20 decibel is 10 times the intensity of 10 decibels, and 50 decibels is 10,000 times as intense as 10 decibels

A noise level above 120 dB can be painful.

Obviously, noise at this level can cause damage to your hearing.

But more importantly, noise levels between 80 and 120 dB can cause "painless" hearing damage – damage that you may not be aware of at the time, but can be causing permanent damage to your inner ear.

What are common problems of hearing protectors ?

Studies have shown that one-half of the workers wearing hearing protectors receive one-half or less of the noise reduction potential of their protectors because these devices are not worn continuously while in noise or because they do not fit properly.

A hearing device that gives an average of 30dB of noise reduction, if worn continuously during an 8-hour workday, becomes equivalent to only 9dB of protection if taken off for one hour in the noise.

This is because decibels are measured on a logarithmic scale, and there is a 10-fold increase in sound energy for each 1dB increase.

During the hour with unprotected ears, the worker is exposed to 1,000 times more sound energy than if ear plugs, muffs or otoplastics had been worn.

In addition, noise exposure is cumulative.

So the noise at home or at play must be counted in the total exposure during any one day.

A maximum allowable while on-the-job followed by exposure to a noisy lawnmower or loud music will definitely exceed the safe daily limit

Even if earplugs and/or muffs are worn continuously while in noise, they do little good if there is an incomplete air seal between the hearing protector and the skin.

When using hearing protectors, you will hear your own voice as louder and deeper.

This is useful sign that the hearing protectors are properly positioned.

What if my hearing is already damaged? How can I tell?

Hearing loss usually develops over a period of several years.

Since it is painless and gradual, you might not notice it.

What you might notice is a ringing or other sound in your ear (called tinnitus), which could be the result of long-term exposure to noise that has damaged the hearing nerve.

Or, you may have trouble understanding what people say; they may seem to be mumbling, especially when you are in a noisy place such as in a crowd or at a party.

This could be the beginning of high-frequency hearing loss; a hearing test will detect it.

If you have any of these symptoms, you may have nothing more serious than impacted wax or an ear infection, which might be simply corrected.

However, it might be hearing loss from noise. In any case, take no chances with noise – the hearing loss it causes is permanent.

If you suspect hearing loss, consult a physician.

This doctor can diagnose your hearing problem and recommend the best way to manage it.