Prosecutors are trying to prove that Reeva Steenkamp did scream and that this showed the star athlete known as the "Blade Runner" knowingly gunned her down in a fit of anger after a row in the early hours of Valentine's Day last year.
The defence claims Pistorius shot the 29-year-old model and law graduate four times through a locked toilet door after mistaking her for an intruder and that any screams came from the double-amputee sprinter himself.
Nel submitted Lin to a technical cross-examination a day after a panel of mental health experts said the 27-year-old Pistorius did not suffer from a mental disorder when he shot Steenkamp and could be held "criminally responsible" for his actions.
Lin said yesterday that at 177 metres away "it is very unlikely a listener can hear a scream let alone interpret the sound source reliably".
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"We have four people identifying the sound of a woman's voice, we have no exceptions," Nel said.
"I do believe they heard a sound but I cannot say whether they were correct or incorrect, it's not for me to interpret that," said Lin.
Later, Nel asked Lin if he thought the state's witnesses were lying. "Not at all," he replied.
Judicial sources say once all the evidence has been presented - estimated to last through the week and prosecution will require a few more weeks to compile their written submissions before presenting them to court.
They will return to court to answer final questions on their arguments.
South Africa does not have jury trials, so a verdict will be delivered by the judge after a few weeks' deliberation.