the voice of joy and the voice of gladness, the voice of the bridegroom and the voice of the bride, the voice of them that say, Give thanks to Jehovah of hosts, for Jehovah is good, for his lovingkindness [endureth] for ever; [and of them] that bring [sacrifices of] thanksgiving into the house of Jehovah. For I will cause the captivity of the land to return as at the first, saith Jehovah.
Jeremiah 33:9 And [this city] shall be to me for a name of joy, for a praise and for a glory, before all the nations of the earth, which shall hear all the good that I do unto them, and shall fear and tremble for all the good and for all the peace that I procure unto it.
Jeremiah 33:10 Thus saith Jehovah: Yet again there shall be heard in this place, whereof ye say, It is waste, without man and without beast, even in the cities of Judah, and in the streets of Jerusalem, that are desolate, without man and without inhabitant and without beast,
Jeremiah 33:11 the voice of joy and the voice of gladness, the voice of the bridegroom and the voice of the bride, the voice of them that say, Give thanks to Jehovah of hosts, for Jehovah is good, for his lovingkindness [endureth] for ever; [and of them] that bring [sacrifices of] thanksgiving into the house of Jehovah. For I will cause the captivity of the land to return as at the first, saith Jehovah.
Jeremiah 33:12 Thus saith Jehovah of hosts: Yet again shall there be in this place, which is waste, without man and without beast, and in all the cities thereof, a habitation of shepherds causing their flocks to lie down.
Jeremiah 33:13 In the cities of the hill-country, in the cities of the lowland, and in the cities of the South, and in the land of Benjamin, and in the places about Jerusalem, and in the cities of Judah, shall the flocks again pass under the hands of him that numbereth them, saith Jehovah.
The verse centers on "voice", "gladness", and "bridegroom". It is saying that the verse draws attention to "voice" and "gladness", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 10's "Thus saith Jehovah Yet again there shall..." into verse 12's "Thus saith Jehovah of hosts Yet again...", so "voice" and "gladness" belong inside that flow. In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "voice" and "gladness" with trust shaped by these words, not by a vague optimism outside the passage.