This week we move on to the fourth in our series of 6 stressors, Sound. We will discuss how sound can be a stressor, what the health impacts can be, and how we can reduce the negative effects on our wellbeing.
It is all around us, from the sound of the refrigerator, to running computers. Sometimes even the ceiling lights give off a low buzz. In the city, it is worse. The hum of traffic, distant construction noise, a neighbour mowing their lawn. Even the coffee shop or restaurant we go to to relax is full of noise, loud speech, and laughter.
We hear noise constantly in our waking hours and it can be difficult to get away from. Often we can become distracted and overwhelmed by the sensory overload.
Sound is measured in decibels (dB). Leaves rustling or a whisper is around 30dB, a normal conversation is around 60dB, a vacuum cleaner is 75dB, and a leaf blower is around 110dB.
We know that exposure to loud noises, or sounds above 85dB, can damage our hearing. The amount of time you can hear the sound before damage occurs decreases the louder the sound is.
Pitch refers to the frequency of the sound which is measured in hertz. Low pitch sounds are things like thunder or a bass drum. Examples of high pitch sounds are a bird whistle or a scream. Humans can hear sounds between 20Hz and 20 kHz.
Sounds below our level of hearing are called infrasound. They can sometimes be felt as vibrations. Whereas sounds above our level of hearing are called ultrasounds.
Infrasound can be caused by natural phenomena such as earthquakes and storms. Some man-made sources include jet planes, heating and ventilating systems in large buildings and wind turbines. Some animals can detect infrasound. This can explain how in some cases animals react prior to an earthquake or are affected by storms.
Even though we can’t hear it, the vibrations caused by infrasound can still affect us. Sometimes called “the fear frequency”, sounds at 17-18Hz (below the range of human hearing ability) can provoke feelings of nervousness, uneasiness, and fear.
Some people are more sensitive to sound than others. Sometimes it is just specific sounds for example Misophonia. This is where certain sounds such as the noise someone makes when they eat, breathe or chew trigger an emotional or physiological response such as anxiety, anger or annoyance.
Hyperacusis is over-sensitivity to normal sounds that would normally be easily tolerated. Studies have found that stress levels are directly correlated with sound hyper-sensitivity in both sexes, with the most pronounced sensitivity in women, particularly after menopause.
Auditory processing and nervous system function are directly related to hormones. Specifically, hormones affected by the circadian cycle, reproductive hormones, and neurotransmitters may explain the link between the increase in sensitivity to noise and menopause.
Come back next week when we will look at the more direct impact noise as a stressor can have on our health and wellbeing.