The two effectors are sound. Sound is the vibrations or movement of the air. And the ear is sensitive to a range of approximately 3 and 12 kHz (a tone can be measured as a sine wave). The change in pressure deforms the tympanic membrane which in turn activates frequency-coded neurons to fire.The second effector is eyes in sight. Your eyes respond to light. This should be right because this is what one of my teachers said to me. Hope this helps