Final answer:
Inappropriate transmission of sound waves into the nasal cavities can occur when there is swelling of the mucosa and excess mucus production, which can obstruct the narrow passageways between the sinuses and the nasal cavity. This can happen during a cold or sinus congestion, causing your voice to sound different. The blockage can also allow the sinuses to fill with fluid, resulting in pain and discomfort.
Step-by-step explanation:
Inappropriate transmission of sound waves into the nasal cavities can occur when there is swelling of the mucosa and excess mucus production, which can obstruct the narrow passageways between the sinuses and the nasal cavity.
This can happen during a cold or sinus congestion, causing your voice to sound different to yourself and others.
The blockage can also allow the sinuses to fill with fluid, resulting in pain and discomfort.