The ARA San Juan went missing Wednesday as it sailed from the extreme southern port of Ushuaia to the coastal city of Mar del Plata.
"We're hopeful this will end soon to remain only as a bad memory", said Maria Morales, mother of crew member Luis Esteban Garcia.
However, Argentine navy spokesman Enrique Balbi later confirmed that the noises were not from the missing vessel and added that they were possibly from the ocean or marine life.
"These ships are following the submarine's planned route, (and are) sweeping the whole area and we also have navy ships sweeping from north to south and from south to north", Galeazzi said.
The noise was heard in the South Atlantic about 220 miles (360 kilometers) from the Argentine coast and at a depth of about 650 feet (200 meters).
Navy spokesman Enrique Balbi says Monday that a USA aircraft was sent to check an area where the noise was heard by two Argentine Navy ships.
"We have 11 ships from the Argentine navy, from municipalities, and from countries that have collaborated with research ships such as Uruguay, Chile, Brazil, Peru, the United States, and (the UK)".
Under normal circumstances, the vessel has sufficient fuel, water, oil and oxygen to operate for 90 days without external help, Balbi said, and the vessel could "snorkel" - or raise a tube to the surface - "to charge batteries and draw fresh air for the crew".
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The communication attempts received were originally thought to indicate that the crew was trying to re-establish contact and had prompted celebrations by family members and officials.
Naval base boss Gabriel Galeazzi said: "The vessel surfaced and it reported a breakdown".
Pope Francis, a native of Argentina, has offered his "fervent prayers" for the missing crew.
With U.S. Navy assistance, the Argentine Navy is racing against the clock in its search along the Patagonia coast. The command includes a remotely operated vehicle and vessels capable of rescuing people from bottomed submarines.
Some relatives of the missing crew members took to social media Monday to ask for support during the search.
After he reported the sub had experienced a "short circuit", he was told to "change course and return to Mar del Plata", said Galeazzi.
One of those on board is Argentine Eliana Krawczyk - who became the first female South American submariner.
'Every minute is oxygen that's worth gold'.