The golden censer maybe very significant. In Numbers chapter 16 censers were used to separate those who "...treated the Lord with contempt." (30) from the rest of the people. Pray that you are on the Lord's side! "And he will send his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of the heavens to the other." (Matthew 24:31).
The voice of God talking? The Lord used thunder and lightning as a part of the "plague of hail" used to help the Israelites get out of Egypt in Exodus 9:13-35. "Give an order now to bring...everything you have...to a place of shelter..." (Exodus 9:19; also note 19:16-20:21++). Will there be a place of shelter for God's elect at this time? Will the Holy City be admitting people at this time? Watch, pray and act as God directs.
If the book of Revelation is visualized as a documentary that is telecast in less than an hour, then visualize 8:2-5 taking about 9 to 10 seconds.
Note: keywords are used throughout this study to find other Bible passages talking about the same event (and/or similar events) to glean more information about the event and/or other things that maybe happening at the same time. "Ask the former generations and find out what their fathers learned... Will they not instruct you and tell you? Will they not bring forth words from their understanding?" (Job 8:8 & 10).