Amelia Earhart's desperate pleas for help heard by dozens after she went missing, researchers say

Amelia Earhart's final calls for help were heard by dozens of people after she disappeared in July of 1937, researchers say.

The final days of the legendary American aviator remains one of the great unsolved mysteries, but the International Group for Historic Aircraft Recovery (TIGHAR) claims that a series of radio messages does prove that Earhart did land and perish near a deserted island in the Pacific.

"Can you read me? Can you read me? This is Amelia Earhart. This is Amelia Earhart. Please come in," a woman named Thelma Lovelace hears in the Canadian province of New Brunswick at 1:30 a.m. on July 7.

Earhart gave her latitute and longitutde, as documented by Lovelace in a book, and added, "we have taken in water, my navigator is badly hurt; (repeat) we are in need of medical care and must have help; we can't hold on much longer."

SEE: Earhart's life and career:

Five days earlier, Earhart and navigator Fred Noonan went missing during their historic effort to fly around the world. Their Lockheed Model 10 Electra had lost contact with the U.S. Coast Guard cutter Itasca, and they never arrived at little Howland Island in the Pacific for a refueling stop.

The U.S. Navy Hydrographic Office put out an "all ships, all stations" bulletin about Earhart on July 2, according the TIGHAR study published this week. The Navy released the aviator's primary frequencies and asked sharp ears to listen.

In all, 50 of the 57 "credible" audio reports were heard by government employees or professional commercial operators, but the quality of the signals were poor. Many stations heard only a background "carrier wave," according to TIGHAR.

Some stumbled upon Earhart's calls for help by accident. Some were found to be believable, others were dismissed.

The commanding officer of the Itasca "categorically dismissed all of the reported post-loss signals," according to TIGHAR, and he even ignored receptions heard from radiomen on his own ship. He asserted that "all available land areas were searched therefore Earhart plane was not on land."

However, researchers at TIGHAR and others believe that the pair landed near Gardner Island, also in the Pacific. The radio messages paint a desperate picture of Earhart's final days.

In one message, a private citizen in Hawaii hears the words "tell husband all right," possibly referring to Earhart's husband George Putnam.

It had previously been known that a 15-year-old girl living in Florida had heard a message from Earhart. Betty Klenck heard, "this is Amelia Earhart. This is Amelia Earhart," and wrote the recording in her notebook.

"Betty's Notebook describes a scene so clearly authentic and so emotionally powerful that her experience tends to overshadow the other 56 credible signals heard in the days following the Electra's failure to arrive at Howland Island," TIGHAR writes. "However, in truth, those receptions constitute a body of evidence far stronger than Betty's alone."