An unwanted , unexpected , unpleasant sound is often referred to as noise
Human ears , are not meant to hear only the pleasant sound . We live in a noisy world. It is believed every cell in the body has ( Auditory ?) sense receptors. But , the noise is perceived only at brain .It is incidental our ears are located right beside the brain , adjacent to parieto -temporal cortex . The auditory nerve has its nucleus located dangerously close to vasomotor centers of brain stem .
.
When excess noise enters our ears it vibrates the brain stem as well . Noise travels in the nervous system as electrical impulse , so it is natural for to expect a spill over to the nearby adrenergic centers .
A sudden explosion or a thunder will skip a few heart beats is it not ? Similarly , when we experience pleasant sound / melody** it soothes the nerves , this forms the basis of musical therapy.
So it is logical to conclude , when the nice music has a capacity to heal , unwanted noise is expected to injure our biological system.
** A rock fan under the influence of drug may feel a every nonsense as melody . . . is a different story !
It is observed strokes and MI are more common in urban areas congested with traffic chaos. Here is an article from European Heart journal with solid evidence on this topic.
Excess noise could result in cerebral or coronary arterial spasm , thrombotic occlusion or even a hemorrhage ?*
- Noise induced adrenergic trigger and spasm of blood vessel
- Adrenergic surge and resultant hypertension
Associated Phenomenon along with noise
- Anger
- Anxiety
- Fear (A noise associated with a missile attack in the war zone )
- Relative hypoxia , Air pollution in noisy environment .
*A distinction must be made between chronic noise pollution vs Acute noise intoxication.
For those who want more depth in this topic , I was surprised to find this exclusive journal that documents noise and human health .
Final message
Excessive noise can have a detrimental effect in the nervous system . Since cardiovascular system is also under neurological command it is expected to share the ill effects.
A comforting news for healthy men and women . Noise per se can not be termed as a coronary risk factor . It can (at worst ) be a trigger for an event in individuals who have other major risk factors.
Dr.S.Venkatesan MD 