It is not that complex.
Save the old height to a variable.
Save the current height to a variable.
Divide both these variables by 100. (This will tell us how many beeps to do)
Compare the variables, if they are different we need to do some beeps.
If the current height beeps is >= 8. Make the beep continuous.
If it is between 1 and 7. Beep that many times.