The screams heard on the night Reeva Steenkamp was killed by Oscar Pistorius could have been as loud as a plane's engine, a court has heard.
On Tuesday, testimony in the murder trial of Pistorius focused on the screams that neighbours heard on the night the Paralympian athlete shot and fatally wounded his girlfriend.
State Prosecutor Gerrie Nel questioned Ivan Lin, an acoustics expert, who had been called by the defence team as part of its effort to suggest some neighbours who said they heard the screams of a woman were wrong, and that they actually heard the high-pitched screams of the double-amputee runner.
Mr Nel asked Mr Lin if he would put the screams at 120 DB, or roughly about as loud as plane engine. According to Sky News, Mr Lin replied: "120 means extremely loud, you can almost hear it 100 metres away. It is a very slight possibility, but it is possible."
Mr Lin has testified that he conducted tests showing ambient noise and other factors can make it difficult to hear accurately from a distance.
Mr Nel said the screams of a woman have a "tonal character" and referred to the testimony of the neighbours who were convinced they had heard a screaming woman.
He told the court: "Four state witnesses all heard screams by a woman. That must be reliable even for a scientist."
Mr Lin responded that he could not say whether the neighbours were "correct or incorrect".
Pistorius has testified that he fired through a closed bathroom door, killing Ms Steenkamp, in the mistaken belief there was a dangerous intruder in his home. The prosecution has alleged that Pistorius, 27, killed the 29-year-old after a Valentine's Day argument in 2013.
Pistorius faces 25 years to life in prison if found guilty of premeditated murder, and could also face years in prison if convicted of murder without premeditation or negligent killing. He is free on bail. If found guilty of the lesser charge of culpable homicide, he could face 15 years or a non-custodial sentence.
On Monday, the court received reports from mental health experts who concluded Pistorius was not suffering from a mental illness when he killed Steenkamp and was able to understand the wrongfulness of what he had done. The reports were compiled during a month of tests at a state psychiatric hospital.
Both the prosecution and his defence counsel accepted the findings of the report, compiled by three psychiatrists and one psychologist, although his legal team called for more time to assess the findings and make some consultations.
The trial continues.