Chilling recordings of frantic phone calls made by passengers of the Costa Concordia to emergency service as the cruise liner was capsizing have been played for the first time in an Italian court.

In tapes played by lawyers for the victims at the trial against captain Francesco Schettino in Grosseto, Tuscany, disoriented passengers were heard crying for help and directions as the ship was plunging deeper into the waters off the island of Giglio.

"Help us please, they don't tell us anything; we have children, I've little kids; help us," a passenger was herd telling an operator with Italy's emergency number 112. "We can't see a thing; the ship is going down more and more."

"They slaughter us like sheep; send somebody, hurry up," the man said in another call minutes later. "They don't want to launch lifeboats; the ship is slanting."

Schettino has been accused of dithering in ordering the evacuation, which he then failed to coordinate properly as he allegedly abandoned the ship with hundreds still on board.

In another recording played in court, Hugo Di Piazza, a technician in the engine room, was heard calming that Schettino ordered the ship to go faster and pass closer to Giglio than in previous occasions.

Prosecutors allege Schettino steered the ship too close to the island of Giglio to perform a sail-past salute. The liner hit a rock, got flooded and capsized eventually causing the death of 32 people.

"We knew about the sail-past salute but he was going too fast," Di Piazza told a friend in a taped phone conversation.

Di Piazza said that Schettino raised the speed from 14 knots to 16.

"I don't know what he intended to do. It was the third time he was getting closer and closer [to the shore]," Di Piazza said.

"It was a kind of challenge against himself."

The technician also described the panic and chaos that fell upon the liner after it hit a reef and started sinking.

"There were people falling into the water; some were swimming, others were thrown form one side to the other of the ship as balls in a pinball machine," he said.

Schettino faces up to 20 years in jail on charges of manslaughter, causing a shipwreck and abandoning ship. He is the sole defendant and denies the charges.