Old notebooks are ace.

Batspeak

We have lost our vespertilian ears. Those silhouetted
flitterers, eating midges before they get around
to eating us, making soundscapes that, like our own
conversations, will echo around endless space
getting fainter by halves: they are lost to us now.

It is not just vampire preference: bats are lucky in Poland
but they still cannot hear them there. And it is not only there,
despite the reputations, that people angle boxes
to lower the sound from clicks to whistles. Everywhere
there is loss and nostalgia for half-heard sounds.