Answer:
The dead spot experienced was due to the effect of sound wave interference
Step-by-step explanation:
Sound wave interference occurs when wave interact. They can interact constructive manner increasing each other's strength and rising the intensity of the final wave produced.The waves can also interact destructively reducing each other's strength and intensity.In some cases, destructive interaction causes a total cancelling of the waves resulting to places where no sound can be heard at all.This area is the dead spot.