Noise Induced Hearing Loss

The hearing loss that is caused due to excessive exposure to loud sound is the noise induced hearing loss. NIHL can be sudden or it can take long time to be noticeable. It can be temporary or permanent. The type and the amount of noise exposure may differentially damage the middle ear or the inner ear structure .Exposure to short duration high intensity noise may result in the damage to middle ear where as a continuous noise for a prolong duration may result in the damage to the structure .

What is “Noise” ?

Noise is any unwanted unpleasant or loud sound that disrupts hearing. Exposure to continuous noise of 85-90db ,over a life time in industrial settings, can lead to a progressive loss of hearing .

Effects of noise on daily living

Noise disturbs activities and communication ,causing annoyance may lead to stress responses, then symptoms possibly illness .Noise disturbs sleep and may increase blood pressure, heart rate, and finger pulse amplitude as well as body movement.

Noise and hearing loss

The hearing loss from excessive noise is a predominant occupational concern. Workplace accident and injuries also can increase due to excessive noise, as workers may not hear warning signal and reduced capability to localize the source of sound. Hearing loss can be preventable through taking appropriate safety measures, such as wearing earplugs or reducing the volume of noise.

Sources of noise

Community noise

All noise emitted from all sources except noise at the industrial workplace.

Main source of community noise includes :

• Road Traffic noise

• Noise from rail roads

• Aircraft noise

• Construction noise

• Noise in building

• Noise from consumer products

• Noise in and around home

Machinery noise :

• Plumbing

• AC

• Telephone

• Water heater

• Dish washer

• Acoustic fan

• Refrigerator

• Gas fire

Minor appliances and small machinery

• Fan heater

• Vacuum heater

• Knife sharpener

• Hair dryer

• Electric grinder

• Radio, tape player

• Whistling kettle

People and animals

• Singing, shouting, and parting

• Fights

• Dog barks

• Musical instruments

• Fire works

• Car

• Children

• Hand tools

Industrial noise

Noise from fixed installations, such as factories or construction sites, heat pumps and ventilation systems on roofs , typically affect nearby communities

People under risk for NIHL

• Factory workers

• Railway workers

• Excessive use of personal amplifiers

• DJs

• People prone to loud machinery noise

• People who settle near traffic

General signs of hearing loss

• Ringing in the ear

• Inability to hear soft and high-pitched sound

• Difficulty understanding conversation at a distance or in crowd

• Muffling of speech and other sounds

• Difficulty understanding speech in noise

• More intently lip reads during conversational speech

• Tired or stressed while listening

• Difficulty in hearing emergency alarms

• Trouble during telephonic conversation

Ear protective device

Ear protection device protects the ear from new hearing damage and is a legal requirement for whenever workers are subjected to noise. All hearing protectors are designed to reduce the intensity of noise to the inner ear. It is necessary for all those are exposed to noise to wear ear protection devices in order to prevent noise induce hearing loss.

There are 3 basic types of ear protection devices available including:

• Ear muffs

• Ear plugs

• Semi inserts

Ear Muffs/ Ear defenders

These are the ear protection devices which has the appearance of head phones, which consist of soft ear cushions that create a seal around the ears and hard outer cups that are joined by a head band.

Ear muffs are the most efficient type of ear protection devices which may provide an attenuation of 50db in certain frequency.

These type of EPDs can be used by the people with minor ear infection.

Ear Plugs

These fit in to the ear canal itself. There are several different types of ear plugs available including Disposable, reusable and permanent. In which disposable is for one time use and provides an attenuation about 25 - 30dB. Reusable devices can be washed with soap and use again. It provides an attenuation about 20 – 25dB. Permanent or custom-made ear plugs attenuates 25 – 30dB.

Semi inserts

Semi inserts are earplugs positioned against the ear canal and attached to a small handle which is worn under the chin or around the back of the neck. It provides an attenuation of about 20 – 25dB. The use of Ear muffs in combination with ear plugs provides the best attenuation.

At Bangalore Hearing & Implant Institute, A team of Audiologist and ENTs provide the management options for persons experiencing Noise Induced Hearing loss. For any information connect with us through hello@bhii.info . Ph: +91 6366888883