Position, distance, and location can all change the way you hear sounds. This is the sound of a train horn in the distance versus when it is getting closer and closer. Notice, you may hear vibrations the second time the horn blows. This is because the sound as well as the actual moving of the train caused the ground and my car to vibrate lightly, my phone had touched the car door as I was recording which reflected in the audio. You can also hear sounds of crickets because this was recorded at night in my car as I waited for a train to pass by. There is an abrupt transition in the recording as it goes from far away to close up because the sound was edited to be shorter than the original recording. This was recorded using the voice memo feature on the iPhone 7 Plus.
Walking on gravel in a park of Richmond Virginia during a cold morning. Recorded using a Zoom H1 audio recorder on stereo mode. The sound of the gravel can be heard lightly under the sound of other small brush plant life.