"熙攘喧闹的人群" can be translated into English as "a bustling, noisy crowd" or "a throng of noisy, bustling people".
"Bustling" conveys the idea of constant activity and movement, while "noisy" emphasizes the loudness.
"Throng" is another word for a large, densely packed group of people, often in a lively or chaotic setting.
Both versions capture the essence of the original Chinese phrase.