12th Zoology

Hearing Aid – Noise pollution

Hearing Aid – Noise pollution

Hearing Aid

Patients with a conductive defect which does not respond fully to
treatment may be helped with a hearing aid.
A hearing aid is an electronic, battery-operated device that
amplifies and changes sound to allow for improved communication. Hearing
aids receive sound through a tiny microphone, which then
converts the sound waves to electrical signals. The amplifier increases the
loudness of the signals and then sends the sound to the ear through a speaker
in an ear piece which fits into an outer ear canal. The electric signals are
converted back to sound waves.

A volume control on the aid usually operated by turning a tiny wheel
enables the level of incoming sound to be adjusted.
More powerful aids that amplify sound to a greater
degree are available. In these aids the microphone, amplifier and
battery are contained in a larger case worn on the body; the currents is
carried to the ear piece by a thin wire. Some people with conductive
deafness especially if there is an infection or discharge in the ear canal may
be given a bone condution hearing aid. This type of hearing aid may be fitted
to a glass frame or hair band.

Other devices available for the hard-of-hearing include
amplified telephone receivers, flashing lights instead of door bells and
telephone bells, vibrators that respond to sound, head phone for
television sets, teletype writers and guide dogs for the deaf.

Noise pollution

The term noise is derived from the Latin word Nausea refering to the
feeling of sickness in the stomach with an urge to vomit. Any unpleasant and
unwanted sound is considered as noise. It is one form of pollution. Noise
pollution can be defined as unwanted or offensive sounds that unreasonably
intrude into our daily activities. It is responsible for various adverse effects.
In recent years noise is recognized as a major pollutant on par with other
chemical pollutants of air, water and biosphere. Noise has many harmful
effects on man and the damage incurred is irreversible.

There are various sources of noises and the sources are broadly
classified into industrial sources and non industrial sources. The noise dumped
into the atmosphere by the industires due to the functioning of machineries
form the industrial sources. On the other hand the noise associated with
urban development; road, air and rail transport; loud speakers, radio and
television stations, construction sites, neighbourhood and recreational noise
levels, and activities associated with urban living generally lead to increased
noise levels.

Sound is measured by several complex systems. The best known
unit of measurement is the measurement of sound in decibel which is named
after Sir Alfred Bell. The industrial noise survey of India recognized noise
levels from 81dB to 120dB as permissible levels.

Loud noises (above 130 dB) can cause immediate and permanent
damage to the muscles in the middle ear, altering the stiffness of the ossicles,
damaging the hair cells of the cochlea and casuing the rupture of ear drum
thereby reducing the efficiency of hearing.

Prolonged exposure to unpleasant noises may lead to severe mental
distubances and violent behaviour. Noise is also partially responsible for the
increased consumption of alcohol, drugs, tranquillzers and sleeping pills. Noise
pollution further contributes to a few cardiovascular problems. Peptic ulcers
and asthma are aggravated. Small vessels to glomerular circulation are
subjected to vaso constriction and ultimately the output of urine is reduced.

Persons exposed to excessive noise at work place have temporary
impairment of hearing.

Related Topics in Zoology:

Bio Zoology All Important Topics

  1. Human Physiology Introduction

  2. Nutrition

  3. Carbohydrates Poly hydroxyaldehydes (or) ketones

  4. Proteins (Polypeptides)

  5. Lipids

  6. Vitamins – Functions Of Vitamins

  7. Deficiency of Vitamin

  8. Minerals – Water – Role of water

  9. Balanced diet

  10. Obesity

  11. Digestive System

  12. Dental Caries (Tooth decay)

  13. Root Canal Treatment

  14. Peptic ulcer

  15. Hernia and Types

  16. Appendicitis (Appendix)

  17. Gall Stones

  18. Hepatitis

  19. Fractures – Types of fractures

  20. Mechanism of fracture

  21. Dislocation of joints

  22. Arthiritis

  23. Rickets and Osteomalacia – Orthopedics

  24. Muscles

  25. Mechanism of muscle contraction

  26. Types of muscle contraction

  27. Myasthenia Gravis

  28. Respiration – Process of pulmonary respiration

  29. Mechanism of Breathing

  30. Regulation of Respiration

  31. Pneumonia Tuberculosis Symptoms Treatment

  32. Bronchitis – Acute bronchitis, Chronic Bronchitis Causes

  33. Circulatory System – Functioning of Human heart

  34. Cardiac Cycle

  35. Coronary blood vessel and its significance

  36. Myocardial infarction

  37. Angina pectoris

  38. Angiogram – Angioplasty

  39. Atherosclerosis

  40. Heart block Echo cardiography Heart Valves

  41. Rheumatic Heart Disease (RHD), ICCU – (Intensive Coronary Care Unit)

  42. Blood Pressure

  43. Heart transplantation

  44. Pulse rate

  45. Cardio Pulmonary Resuscitation (CPR)

  46. Blood – Composition of plasma – Blood cells

  47. Clotting of Blood or Haemostasis

  48. Thrombosis

  49. Nervous system Co-ordination systems

  50. The Brain – Fore Brain, Midbrain, Hindbrain

  51. Memory

  52. Sleep – Types of sleep

  53. Stroke – Brain haemorrhage

  54. Alzheimer – Meningitis (Brain fever)

  55. Conditioned reflex

  56. Electroencephalography EEG

  57. Right and Left brain concept

  58. Spinal cord functioning

  59. Chemical co-ordination – Functions of Endocrine glands

  60. Hypothalamus

  61. Pituitary gland – hormone

  62. Hormones of Neurohypophysis – vasopressin

  63. Thyroid gland

  64. Parathyroid Gland

  65. Pancreas

  66. Adrenal gland

  67. Gonads

  68. Receptor Organs – Eye

  69. Photochemistry of Retinal visual Pigments

  70. Errors of refraction

  71. Optometry – Retinopathy

  72. Cataract – Lens Replacement – Glaucoma – Nyctalopia

  73. Eye Infections and Eye Care

  74. Ear

  75. Mechanism of hearing

  76. Defects of the ear

  77. Hearing Aid – Noise pollution

  78. Skin and functions of skin

  79. Melanin functions

  80. Effects of solar radiation / UV radiation – Skin grafting

  81. Dermatitis

  82. Tongue – Mechanism of Stimulation

  83. Excretion Ureotelism Nephron

  84. Mechanism of urine formation

  85. Renal Failure, Dialysis, Kidney Machines

  86. Kidney stone – Kidney transplantation

  87. Diabetes mellitus

  88. Functioning of male reproductive system

  89. Functioning of female reproductive system

  90. Ovulation and fate of the ovum – Menstrual cycle

  91. Fertilization

  92. Birth control

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