Chief prosecutor Gerrie Nel has questioned an acoustics expert who was called by the defence team as part of its effort to suggest some neighbours who testified they heard the screams of a woman were wrong.
They argue the witnesses actually heard the high-pitched screams of the double-amputee runner.
Pistorius fatally shot Reeva Steenkamp through a closed toilet door in his home in the early hours of February 14 last year. Acoustics expert Ivan Lin testified he conducted tests that showed ambient noise and other factors can make it difficult to hear accurately from a distance.
The prosecution has alleged that he killed Ms Steenkamp after a Valentine's Day argument.
The trial continues.