“The role of the ear in chameleon biology has received little attention because their ears are typically considered vestigial and barely functional. However, the widespread occurrence of a well-developed tympanic cavity, repeated evolution of a novel sound conduction pathway, and possible shifting of muscle insertions to accommodate the ear highlight the potential significance of the ear for many chameleons. Further research is needed to understand exactly how these ears are used. Such inquiries will likely reveal a complex and interesting evolutionary history that may inform the origin of the ear in other clades, as well.”…
https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.24879
https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.24879