"The voice of one of them has been identified. The voice of another is still to be established by the Polish side," said Tatyana Anodina, head of the Interstate Aviation Committee.
The voices initially were difficult to discern because the door to the cockpit was open, ITAR-Tass reported Wednesday.
"Unique equipment was used to clear the recording of the noises," Anodina said. "As a result the voices were identified quite distinctly."
Anodina did not say specify who had been identified.
The crash April 10 near the western Russian city of Smolensk killed all 96 people aboard, including Polish President Lech Kaczynski and other top Polish officials.
Russian air traffic controllers repeatedly warned the crew of the Soviet-made Tu-154 not to land because of poor visibility, RIA Novosti reported.
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