An elephant call can be described as deep, rumbling, and resonant, often carrying over long distances. The sound can range from low-frequency rumbles to loud trumpet-like calls, conveying different emotions such as excitement, distress, or warning to other elephants in the herd.
You write sizzle.
baaah
bacock
squeak
BOOM!
ting
You could write Bzzzz or Zzzz or any other buzzing sort of sound.
The sound a whistle makes is often described as "whoo" or "wee" depending on the pitch and intensity of the sound.
"bzzftt"
dribble dribble
BWAAAAAAAAAAAAAAAAAAAAAAAAA~!!! At least that's the sound he makes around here.