This device covers both ears and includes a band across head. The thing Uhura wears is teS HablI'. (qep'a' 2020)This only applied to a complete set, and not to single earbuds. teS HablI' was defined as "the thing Uhura wears" simply because Okrand didn't know the word for it. (qep'a' 2020 Q&A 35:50)