Use the adverb simultaneously to describe actions that occur at the same time. You are reading this sentence and simultaneously learning a new word! Simultaneously doesn't have to describe two different actions. It just means that things are happening at the same time.

What part of speech is simultaneous?

SIMULTANEOUS (adjective) definition and synonyms | Macmillan Dictionary.

Is concurrent an adverb?

CONCURRENTLY (adverb) definition and synonyms | Macmillan Dictionary.