This is not true at all. A mature 4 or 5 pointer can scream as loud or louder as an elk with the largest rack. Or vice versa, the elk with the large rack may be loud. This is just not a good way to determine anything about the elk other than he has a loud voice. This really intensifies during the rut.
Many outdoorsmen believe that unseasonably hot weather can delay the breeding season.
This is simply not true, but an early cool season can help speed up the rut. What seems to impact the arrival of the rut more than anything is the amount of daylight in each day. Hormonal changes will start ocurring as soon as the days begin getting shorter. For weeks during the rut, a harem bull has a full time job of keeping his group intact. He is constantly rounding up wandering cows and drives away would be rival bulls.