Deuteronomy says the Israelites heard Yahweh. Exodus implies (I think strongly, in two different ways) that they didn't.
Deut 4:12 ([NASB])
Then the Lord spoke to you [the Israelites] from the midst of the fire; you heard the sound of words, but you saw no form — there was only a voice.
But Exodus has Moses relaying Yahweh's words to them, suggesting that they couldn't hear directly:
Ex 24:3 (NASB)
Then Moses came and reported to the people all the words of the Lord and all the ordinances; and all the people answered with one voice and said, “All the words which the Lord has spoken we will do!”
and, while Moses is receiving the revelation, the Israelites give him up as lost:
Ex 32:1 (NASB)
Now when the people saw that Moses delayed to come down from the mountain, the people assembled around Aaron and said to him, “Come, make us a god who will go before us; for this Moses, the man who brought us up from the land of Egypt—we do not know what happened to him.”
It seems to me that Moses relaying the words of Yahweh to the Israelites strongly implies that the Israelites couldn't hear the words in Yahweh's voice. It also seems to me that the Israelites giving Moses up for lost while the revelation was ongoing again strongly implies that they couldn't hear the words in Yahweh's voice. To illustrate the point, suppose they could hear. Then we might read something like,
Ex 24:3 (changed to illustrate Question)
Then Moses came and reported to the people all the words of the Lord And the people replied, "Why are you telling us what we have already heard?"
Ex 32:1 (changed to illustrate Question)
Now when the people saw that Moses delayed to come down from the mountain, the people assembled around Aaron and said to him, “Come, make us a god who will go before us; for this Moses, the man who brought us up from the land of Egypt — we do not know what happened to him.” And Aaron said to the people, Can you not hear the LORD speaking to Moses even now? Listen, the voice of the LORD is like the thunder of heaven. And the people replied to Aaron, "Speak louder, for we cannot hear you."
The apparent inconsistency is that Deuteronomy and Exodus appear to give different accounts of the Sinai revelation.
Deuteronomy says the Israelites "heard the sound of the words but saw no form". Exodus says that some of the Israelites did see a form, and the Israelites as a whole gave up Moses for lost while the revelation was ongoing, suggesting they couldn't hear it.
Origin of this question
At the suggestion of Jesse Steele, I (re-)add some information about Margaret Barker, who prompted this question.
In her book, Introduction to Temple Mysticism (ISBN-13: 978-0281056347; second page of the Introduction chapter in the version I'm looking at), Barker writes,
Deuteronomy denied that the LORD could be seen, and in the Deuteronomists’ account, when the commandments were given to Moses ‘you heard the sound of words, but saw no form’ (Deut. 4.12). The other version of Moses receiving the commandments says that he and others saw the God of Israel (Exod. 24.10), and we can only assume that the writer of Deuteronomy was contradicting this.