Answer:
The girl hears the ambulance sound different. The first part of the picture shows the girl and the sound waves, and they are right in front of her, so she cannot hear them as well. But the second image shows the girl in the middle of the sound waves. This is the strongest and loudest part of the sound waves, so it sounds different to the girl in the image.
Also, in the first image, the sound waves would most likely sound higher than in the second image. The sound would continue to get lower in frequency the father it drove away. This is because of the Doppler Effect. The Doppler Effect refers to the change in wave frequency during the relative motion between a wave source and its observer.
Explanation: