Final answer:
The loudness of a sound from a balut vendor is less heard in colder times because colder air is denser, hindering the sound waves' ability to travel. Insulated homes in Northern Europe stay warm by trapping body heat and preventing heat loss.
Step-by-step explanation:
The question revolves around the phenomenon of sound propagation and how it is affected by temperature. When it is colder, the air is denser, causing sound waves to travel more slowly and with less energy compared to when it is warmer.
Consequently, a balut vendor shouting from your neighbor’s house would be less heard during colder times. This is due to the fact that when air molecules are cold, they are closer together and vibrate less, making it harder for sound waves to transfer energy between them. This effect of temperature on sound propagation is also taken into consideration in engineering and environmental sound studies.
To amplify the effect of warmth in insulated homes without traditional heating systems, they rely on body heat and good insulation, which traps heat and prevents rapid heat loss, maintaining a warmer interior even in the absence of residents.