/usr/lib/x86_64-linux-gnu/libecasoundc.so is in libecasoundc-dev 2.9.1-7+b2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libecasoundc.so.1.1.0
/usr/lib/x86_64-linux-gnu/libecasoundc.so.1.1.0