star trek - What did the probe and the whales say to each other?

The film's official novelisation contains a version of events that includes a translation of the probe's conversation with the whales. Apologies for the length of the quote:

[Probe] Why did you remain silent for so long?

They [The whales] tried to explain, but it reacted in surprise and disbelief.

Where were you? it asked.

We were not here, they replied, but now we have returned. We cannot explain, traveler, because we do not yet understand all that has happened to us.

By "us," the traveler understood them to mean themselves as individuals and all their kind for millions of years in the past. By their song it recognized them as youths.

Who are you? it asked. Where are the others? Where are the elders?'

They are gone, the whales sang, with sadness. They have passed into the deep, they have vanished upon white shores. We alone survive.

Your song is simple, the traveler said, chiding. It was not above petulance. Where are the tales you have invented in all this time, and where are the stories of your families?

They are lost, replied the whale song. All lost. We must begin again. We must evolve our civilization again. We have no other answer.

The traveler hesitated. It wondered if perhaps it should sterilize the planet anyway despite the presence of the untaught singing youths. But if it began a new evolution here, the planet would be silent at least as long as it would take the traveler to circumscribe the galaxy. The traveler would have to endure the pain of the world's silence. Organic evolution required so much time. Besides, the traveler possessed very little cruelty. It could consider destroying the young singers, but the conception caused great distress. It abandoned the idea.

Very well, it said. I shall anticipate young stories.

Fare thee well.

The traveler fell silent. The whales bid it farewell. The traveler collected its energy. It ended its interference with the patterns of the blue-white planet. It ceased to power the violent storms ravaging the surface. It sought its usual course, oriented itself properly, and sailed on a tail of flame into the brilliant blackness of the galaxy.