OET interlinear REV 4:1

uW Translation Notes:

Note 1 topic: figures-of-speech / ellipsis

θύρα ἠνεῳγμένη ἐν τῷ οὐρανῷ, καὶ ἡ φωνὴ ἡ πρώτη

˓a˒_door ˓having_been˒_opened_up in ¬the heaven (Some words not found in SR-GNT: Μετά ταῦτα εἶδον καί ἰδού θύρα ἠνεῳγμένη ἐν τῷ οὐρανῷ καί ἡ φωνή ἡ πρώτη ἥν ἤκουσα ὡς σάλπιγγος λαλούσης μετʼ ἐμοῦ λέγων Ἀνάβα ὧδε καί δείξω σοί ἅ δεῖ γενέσθαι μετά ταῦτα)

John is leaving out some of the words that in many languages a sentence would need in order to be complete. You can supply these words from the context if that would be clearer in your language. Alternate translation: [I saw a door opened in heaven and I heard the first voice]

Note 2 topic: figures-of-speech / activepassive

θύρα ἠνεῳγμένη ἐν τῷ οὐρανῷ

˓a˒_door ˓having_been˒_opened_up in ¬the heaven

If your language does not use this passive form, you could express the idea in active form or in another way that is natural in your language. Alternate translation: [an open door in heaven]

Note 3 topic: figures-of-speech / metaphor

θύρα ἠνεῳγμένη ἐν τῷ οὐρανῷ

˓a˒_door ˓having_been˒_opened_up in ¬the heaven

John is speaking as if there were literally a door leading into heaven through which he could see. If it would be clearer in your language, you could state the meaning plainly. Alternate translation: [I could see through an opening into heaven]

Note 4 topic: figures-of-speech / simile

ὡς σάλπιγγος

like ˓a˒_trumpet

The point of this comparison is not that the sound of the voice was like the sound of a trumpet but that the voice was loud like a trumpet. If it would be helpful in your language, you could make this point explicitly. Alternate translation: [that had been loud like the sound of a trumpet]