Oscar Pistorius' lawyer Barry Roux questioned whether witness Michelle Burger knows the difference between a male and female scream and gunshots and the sound of a cricket bat hitting a door on Day Two of the sprinter's murder trial.
Burger, who is a university lecturer, lives 187 meters from the South African athlete's home. On Monday, Burger testified that she heard a "blood-curdling" scream and then "four gunshots" on the night Pistorius' girlfriend Reeva Steenkamp was slain.
The trial continues.