In the message, she asked her son to bring her coat when he came to meet her at Beijing airport on March 8, 2014.
It's been more than 500 days since the flight veered off course and disappeared without trace en route from Kuala Lumpur, Malaysia.
The last time Wang listened to the message was last week, when news emerged that beach cleaners had found a barnacle-encrusted piece of plane debris on the French island of Reunion in the western Indian Ocean.
The object -- now confirmed to be part the wing of a Boeing 777, the same model of plane as Flight 370 -- has raised hopes that it could peel back some of the layers of mystery that shroud the fate of the Malaysian plane and the 239 people aboard.
Experts are due to start analyzing the wing component, known as a flaperon, at a lab in a suburb of the French city of Toulouse on Wednesday. It's unclear how long it will take to determine whether it's from MH370.
But even if it is confirmed to be a part of the lost passenger jet, Wang says it won't change much for him.
"It still cannot help you find the plane," he told CNN. "And it still cannot help you find the truth about what happened."
Australian official: New object is a piece of a ladder
Other bits of debris are turning up on Reunion Island, but officials have discounted many of them.
A metal "object of interest" was found on a beach Sunday in Saint-Denis, the island's capital, authorities said, setting off speculation that it could be part of a plane.
But the head of the Australian agency leading the underwater search for MH370 discounted that notion.
"It was quite easy to determine, after some visual inspection, that it wasn't anything to do with an aircraft," Martin Dolan, chief commissioner of the Australian Transport Safety Bureau, told CNN's "New Day" on Monday.
"It was, in fact, part of a domestic ladder."
Lab work to begin
The French military agency that operates the lab where the flaperon will be examined has sophisticated equipment and expertise to quickly identify which plane the debris belongs to and what happened to it, a source close to the French investigation told CNN last week.
The analysis could reveal details about the plane's final moments -- whether it crashed into the sea or broke apart in midair, for example.
But it's unlikely to solve the puzzle of why the plane turned sharply off its scheduled flight path or where it exactly in the Indian Ocean it ended up. Australian officials have said they don't plan to change the area of the underwater search for the plane's wreckage in the eastern Indian Ocean.
The remnants of a suitcase, which were discovered on the Reunion coast the day after the flaperon, is being sent to criminal research institute in Pontoise, outside Paris.
French and Malaysian officials held a closed door meeting in Paris on Monday.
More objects found, none with confirmed links to plane
On Reunion Island, the search for more debris that might be linked to MH370 is continuing, with many people combing the shoreline near where the flaperon was found.
But so far, officials haven't reported any leads as strong as the wing component.
"Today, a lot of people go to the beach and bring objects to the police, but we think it is nothing," Jean-Yves Sambimanan, a city hall official from Saint-Andre, the town where the plane part was found, said Sunday.
Other islands on the lookout for debris
Searchers are also scouring the waters around Mauritius, an island nation about 175 kilometers (110 miles) east-northeast of Reunion, authorities said.
"We are giving our full support since the debris has been found on Reunion Island," said Mauritius Police Sgt. Indira Bhugobaun.
Coast guard vessels and aircraft have been conducting searches since Saturday and are expected to continue until around Thursday, police said.
The coast guard in the Seychelles, an island chain about 1,800 kilometers (1,100 miles) north of Reunion, said it has been instructed to be on the lookout for possible debris.
The Malaysian government said Sunday that the country's civil aviation authority was reaching out to its counterparts in territories near Reunion and elsewhere in the Indian Ocean to ensure expert analysis of any debris that might be found.
But bits of debris aren't likely to bring closure for Wang and other family members of those on board Flight 370.
"I think the only closure would come at the time when they find the plane and find everybody -- and find the truth," he said.