Nel questions Pistorius's sound expert

The State on Tuesday (01/07/2014) cross-examined an acoustics expert who testified for the defence in the trial of murder-accused paralympian Oscar Pistorius.

Prosecutor Gerrie Nel questioned Ivan Lin's report in the High Court in Pretoria on ambient noise on the morning of Valentine's Day last year, when Pistorius shot dead his girlfriend Reeva Steenkamp.

Nel asked Lin when the report was compiled. Lin said he began working on it "more than a week ago" and completed it "sometime last week".

"When you went to the scene last week it was more than a year [later]. Trees have grown, houses were built. How did you know [the scenario]?" Nel asked.

Lin said: "There was no scenario put to me, I had to explore different possibilities."

He did not have access to Michelle Burger's home, which was 177m from Pistorius's.

Burger, the first State witness to testify in the trial, told the court in March she heard "blood-curdling screams" followed by four gunshots.

She said she and her husband were woken in the early morning by the sound of a woman screaming.

Nel asked Lin if one could be certain they were hearing the screams of a woman or man. Lin said it was all based on the listener's perception.

"No one can say all perception is reliable."

Pistorius shot Steenkamp through the locked door of his toilet in his Pretoria home, apparently thinking she was an intruder about to open the door and attack him.

She was struck in the hip, arm, and head. After firing the shots, Pistorius used a cricket bat to break open the door to get to a dying Steenkamp.

He has pleaded not guilty to the charge of the murder as well as not guilty to three firearm-related charges.

The State argues he killed her during an argument. - Sapa