For many economic decisions, people rely on secondhand information received from others by word of mouth. Does the process of oral transmission systematically distort economic information? In our experiment, participants listen to audio recordings containing forecasts of economic quantities and are paid to accurately relay the information via voice messages. Other participants listen either to the original recordings or transmitted versions of them and then state incentivized beliefs about the economic quantities. We show that information about the reliability of a forecast is much more strongly lost in transmission compared to the content of the forecast itself, and that this predictably distorts the posteriors of recipients of transmitted messages. Transmission-induced loss of reliability information dramatically increases the influence of unreliable forecasts relative to reliable forecasts on beliefs. We investigate potential mechanisms behind this differential information loss and provide evidence that difficulty articulating information about reliability plays an important role.