Sound is converted to an electrical signal when it enters the ear. This signal travels up the auditory nerve to the part of the brain that processes sound, the auditory cortex. From there, the signals travel throughout the brain, creating a variety of responses. The effects of sound in the brain include evoking emotions, triggering the release of stress chemicals and impacting the development of new neural pathways in the brain.
Music impacts the part of the brain that controls the link between sound, memories and emotion, the medial prefrontal cortex, says the National Institutes of Health. Listening to music can soothe the emotions. A study published in the December 2009 journal Pediatrics found that premature babies demonstrated an increased rate of weight gain when they were exposed to music by Mozart. The music soothed the babies, reducing their resting energy expenditure. Researchers speculate that the weight gain seen in premature babies who are exposed to Mozart results from this lower energy expenditure.
In May 2006, the Journal of Advanced Nursing reported that people who listen to music experience less pain and lower levels of depression and disability related to pain than those who don't listen to music. This indicates that music can effect the brain by lifting the mood and alleviating the perception of pain.
Loud noises evoke an instinctive fight or flight reaction in the brain, according to The Franklin Institute. The fight or flight reaction is a release of chemicals that stimulates immediate action. This reaction has been crucial to ensure human survival in the wilderness, and remains important in the modern world. If you hear a loud honk from a car horn, your brain and body respond quickly to move you out of harm’s way. Once danger has passed, the brain releases tranquilizing chemicals that counteract the stimulating chemicals.
Exposure to too many loud noises can overload your brain with stimulating chemicals. Without the balancing effect of the brain’s tranquilizing chemicals, the stimulating chemicals can damage brain cells. The world is full of noise, from the thumping bass in a teenager’s car to the roar of jet engines and the perpetual sound of televisions and chatter. Solutions include wearing noise-deadening headphones when they can be safely used, using sound-proofing materials in your home, and making choices to turn down controllable noise sources such as the television or stereo.
Neural Pathway Development
The Child Welfare Information Gateway notes that the sound of speech has an important effect on the brains of babies, helping them develop the neural pathways that organize speech and language. Babies exposed to the sound of speech develop strong pathways, and the more speech sounds they are exposed to, the stronger these pathways become. Babies that receive limited exposure to speech sounds do not develop these pathways, and any unused pathways that have developed are discarded by the brain.