The recording was made by someone on a mobile standing roughly ten metres lower and away from Saddam.
The taunts sound loud(ish) on the recording. But the microphone on the mobile phone would clearly and loudly pick up the sounds of the people standing besides the person with the mobile.
Saddam would not have heard those taunts as loudly as they come across on the recording. He was ten metres away and well above the taunters.
Whatever took place, it was nothing compared to the torture meted out by Saddam during his life. When you compare his execution to the Romanovs and the Ceausescus, they had no trial and were hurriedly shot like dogs.
In contrast, Saddam had three years gardening leave, a long trial (of sorts), and a hangman who looks as though he was particularly kind at the end.