1. The problem statement, all variables and given/known data A car with a 1000Hz siren moves away from you toward a cliff at 15m/s. You are stationary. What frequency of sound do you hear directly from the wall and what frequency do you hear reflected off the wall? Which sound is louder? 2. Relevant equations f' = f(v +/- vo)/(v +/- vs); where v = 343m/s, vo = velocity of observer, vs = velocity of the source 3. The attempt at a solution I found that the frequency of the sound you hear directly is 958Hz and the frequency of the echo is 1046Hz. How can I tell which one is louder?