Final answer:
Echoes are the first few reflections that reach the listener within a space, as they are sound waves that are reflected back from large surfaces allowing a repetition of the original sound to be heard.
Step-by-step explanation:
The first few reflections that reach a listener within a space are echoes. An echo occurs when sound waves that travel through the air collide with a large surface and are reflected back. This phenomenon allows a person to hear a repetition of the original sound after a brief delay. For instance, if you were to loudly say 'hello' in a large, empty hall, you would experience your voice as an echo returning to your ears. Reverberation, although related, refers to the multitude of reflections that build up and then decay as sound is absorbed by the surfaces of the room and the air. Resonance is a specific phenomenon where the frequency of the sound waves corresponds with the natural frequency of the space or object, causing an amplification of the sound.