Literally, everything will make a sound when it is not calm. A metaphor for "expressing indignation at unfair things".
In the study of literary criticism, people often use the expression "injustice makes a sound" to illustrate the positive role of the unfortunate and painful life experiences of poets and writers in their creation. It is reasonable to regard it as the same theoretical source as "writing books in anger" and "working after poverty", but it still needs a little analysis to understand the original intention of "complaining when there is injustice" more comprehensively and accurately.