According to ubuntu manual:
ldconfig creates, updates, and removes the necessary links and
cache (for use by the run-time linker, ld.so) to the most recent
shared libraries found in the directories specified on the command
line, in the file /etc/ld.so.conf, and in the trusted directories
(/usr/lib and /lib).
So, assuming that freeverb.so is located in /home/yourUser/Download directory (folder), create folder in your home:
and copy freeVerb.so library:
cp /home/yourUser/Download/freeverb.so /home/yourUser/myLibrary
create a simple file freeverb.conf like this:
echo "/home/yourUser/myLibrary" > freeverb.conf
Add you configuration file freeverb.conf in /etc/ld.so.conf.d directory (in this directory you can find files as example)
sudo cp freeverb.conf /etc/ld.so.conf.d
ldconfig in order to configure dynamic linker run-time bindings.
If /etc/ld.so.conf.d doesn't exists, you can add your path at the end of /etc/ld.so.conf file.
At the end, if all went well, you can remove unnecessary file: