[gentoo-user] [OT] splitting audio file at points of silence ?

Hi,

I want to split an audio file containing crow calls at points
where no crow call is. The "silence" in between is not exactly
"silence" but some low level noise.

Searching the internet for "split audio at silence" and similiar
gives me this link
https://unix.stackexchange.com/questions/318164/sox-split-audio-on-silence-but-keep-silence

which uses a program called "silence" to detect the silence.

Unfortunately I can't figure out, what package contains that program
or from where I can download that program.

The input audio is a flac file  and I don't want to convert this into
any lossy audio format to preserve as much as possible of the signal.

Where can I get this program ?

or

How can I split an audio file at points of defineable 
level of "silence" into several audio files in one go?


Cheers!
Meino