The human subject becomes conscious of the divine through hearing and obeying. It is a sweeping and reassuring judgment that orders our knowledge of antiquity with a tinge of superiority. Surely a religion based on experiencing the transcendent through sound rather than sight has registered a significant advance. The midrash is not hesitant about speculating that the Israelites themselves were divided about how they wished to meet God at Sinai. The occasion is the narrative describing what God asked of Israel prior to the moment of revelation.
Rabbinic imagination fills in the gap.
This midrash is not a case of imagination run wild. The divergence of opinion is not imputed into the biblical text but extracted and elaborated. With great sensitivity, the Rabbis noticed that in the space of a few verses the Torah switches its vocabulary from sound to sight. The linguistic hints seem to suggest a swirl of conflicting emotions just beneath the surface of the text. The midrash is untroubled by the lack of consensus.