Sounds in Nature

In this week’s lecture, we learned about different types of rhythms, sounds, and frequencies within our body. We explored topics like the circadian rhythm, brain waves, heart rhythm, and sound frequencies that we could hear. Circadian rhythms are 24-hour cycles that are part of the body’s internal clock that runs in the background for our essential functions and processes. Although circadian rhythm regulates the internal body, it is directly influenced by environmental cues, especially light. That is why circadian rhythms are tied to the cycle of day and night. One of the most important and well-known circadian rhythms is the sleep-wake cycle. In our brain, we have different waves named as beta, alpha, delta, theta, and gamma. Brain waves are electrical impulses in the brain and are produced by synchronised electrical pulses from communication of neurons. They occur at various frequencies and some are fast while some are slow. And this difference in frequency could also be affected by the environment. For instance, based on a research study in 2016 by a group of Portugal scientists, in hot thermal environments, activity of alpha waves tends to decrease and beta activity is relatively the same (1).


After learning and researching about the interconnectedness of the rhythms and waves between environment and body, for this week’s assignment, I decided to connect the lecture material into the environment surrounding me. On a sunny afternoon, I went to my backyard and started to record the sound. In this audio I clipped, there were sounds like birds chirping, wind blowing, leaves rustling, and blinds clattering. I always enjoy the bird chirping sounds as if I am embraced by nature. From lecture, I learned that humans can hear between about 100 and 10,000 hertz. Many bird songs have frequency ranges between 1,000 Hz and 8,000 Hz, which places them in the sweet spot of human hearing (2). And there are bird chirping humans could not hear, which includes sounds from many warblers, sparrows, waxwings, and kinglets that produce sounds that reach 8,000 Hz and beyond. Bird chirps for a number of reasons ranging from asking for food to attracting opposite sexes. A similar action to human whistle, which has frequency of 500-5,000 Hz, is also produced for gathering attention.


There were also sounds of wind blowing, which makes the rustling leaves and clattering blinds sound. According to, I was experiencing a light breeze that has a speed of 4 to 7 mph (3). I could feel the wind on my face, hear leaves rustle, and see small twigs move. My window blind was blown up a bit and created the rattling sounds. Then I remembered that wind is also needed for the newbie birds to learn how to fly. When wind moves toward a bird, its spread wings can hold the bird up. The bird then can move along the air currents. I rarely thought about the sounds I could explore in my environment since I usually play music while working and studying. During that day in my backyard and listening to my surroundings, I found myself immersed in the sounds of nature and exploring the interconnection of every bit of natural occurrence.