My understanding is that our own equipment could only discern our own signals out to about 4 light years. I suspect all that could be discerned from a farther distance would be an odd intermittent radio hash.
Thus any signal from life on other planets would require equipment at least a magnitude stronger (better?) than ours.
The distance limit in 1960 was in the area of 4 ly. Twenty years later or so it had risen to better than 10 ly (which is obviously more than 2.5 times as much space that could be listened to), and sensitivity has risen a lot since then. The next big leap *may* be radiotelescopy from the “dark side” of the Moon.