Your teacher is somewhat correct. The amplitude is only associated with the actual loudness (volume). You could have a 2000 Hz siren where it would hurt your ears but if it was several hundred meters away it may barely be heard but it would still be 2000 Hz. However I think your teacher is referring to what we perceive. Our ears are more sensitive to the range 2000 Hz to 8000 Hz so a 100 Hz tone and a 2000 Hz tone with the same amplitude may not appear equally loud to us. The 2000 Hz tone would sound louder.
