I n Guide for the Perplexed 2:36 Rambam discusses the physical, emotional, and intellectual prerequisites to prophecy. At the conclusion of the chapter he explains that loss of the prerequisites caused the loss of prophecy, and also points to Scriptural allusions:
The same circumstance, prevalence of sadness and dulness, was undoubtedly the direct cause of the interruption of prophecy during the exile: for can there be any greater misfortune for man than this: to be a slave bought for money in the service of ignorant and voluptuous masters, and powerless against them as they unite in themselves the absence of true knowledge and the force of all animal desires? Such an evil state has been prophesied to us in the words, "They shall run to and fro to seek the word of God, but shall not find it" (Amos viii. 12); "Her king and her princes are among the nations, the law is no more, her prophets also find no vision from the Lord" (Lam. ii. 9). This is a real fact, and the cause is evident; the pre-requisites [of prophecy] have been lost. In the Messianic period--may it soon commence--prophecy will therefore again be in our midst, as has been promised by God.
The Sages of the Talmud may have read these verses and noticed these observable phenomena.