Tina is waiting at the bus stop. She sees and hears an ambulance as it approaches and passes by her. Which two changes in the loudness of the siren does Tina hear? The sound becomes less loud as the ambulance approaches her. The sound becomes louder as the ambulance approaches her. The loudness of the sound remains the same as long as she can see the ambulance. The sound stops when it reaches her. The sound becomes less loud as the ambulance moves away from her.