In Revelation 14:2, 'the voice of great thunder' signifies the Lord speaking through the New Heaven from Divine Love; it also signifies a glorification of the Lord from His celestial kingdom. (Apocalypse Revealed 615, Apocalypse Explained 855)

'Voices,' 'lightnings,' and 'thunders,' as in Revelation 16:18, signify rationalizations, falsifications of truth, and arguments grounded in falsities that stem from evil in the church among people who believe in salvation by faith alone. (Apocalypse Explained 821[4], 1014)

(Reference: Apocalypse Revealed 710)