This is the 6469th most frequent Japanese word.
スーーーッ
"スーーーッ" describes a smooth, unobstructed motion or clean sensation, like something gliding or feeling refreshed.
Here, 『スーーーッ』 signifies the soft sound of wind passing, used to evoke an auditory imagery associated with nature.
風が木々の間を通り抜ける時、『スーーーッ』という音が聞こえた。
When the wind passed through the trees, a 'suuuuu' sound was heard.
In this sentence, 『スーーーッ』 describes the sound of steam venting out, serving to depict the physical occurrence through auditory description.
蒸気が逃げる際、『スーーーッ』と放出される音がした。
As the steam escaped, a 'suuuuu' sound was emitted.
In this sentence, 『スーーーッ』 represents the sound of taking a breath, emphasizing the audible aspect of the action.