> The world in which we evolved would have been almost silent, almost all of the time, apart from the sounds of birds and insects. I wonder if that hypothesis

> The world in which we evolved would have been almost silent, almost all of the time, apart from the sounds of birds and insects. I wonder if that hypothesis is related at all to hypothesis of bicameralism? https://en.wikipedia.org/wiki/Bicameralism_(psychology) https://en.wikipedia.org/wiki/Bicameralism_(psychology) Note: I haven't read the book, so maybe it was covered...