I am acoustic T-Shirt

Acoustic is a euphemism or algospeak version of the word "autistic" (in reference to autism spectrum disorder), which is sometimes used as a derogatory term or insult to refer to people with mental disabilities but can also be used to describe someone or something exhibiting abnormal behavior in a more lighthearted way. The slang term has been used online since 2016 but it became increasingly prevalent online in early 2023, especially on Twitter / X and some parts of TikTok where users flooded comment sections of videos with the phrase "Is He Acoustic?" in a pejorative tone, referencing the Is He Stupid? meme.