Sound in winter and in the summer

[dg240]

Hello,

I've had a question about sound for a while and finally I found this forum of enthusiasts - so here goes: I notice in the winter the everyday street noise seems to be quite loud. Every time there is a warmer day, and when spring/summer comes, it seems more quiet, more peaceful. Why is that? Is it because the frequencies of sound are higher, and therefore we hear less of the noise? I am not a physicist, but I like to learn... so I hope my questions here won't sound too elementary;) Thank you,

DG

 

[aodesky]

Hello,

The qualities of the medium in which a wave is traveling basically determines the qualities of the wave. When the air is warmer, the molecules are all hitting each other more often then they would on a colder day, and hence they are not as easily shifted as when colder. This is related to how the pressure is higher when the temperature is higher. The sound wave is essentially energy, and the sound that reaches you is the result of the wave after having traveled thru whatever it had to get thru to get to you. In the case of warmer, more rigid air, the wave travels faster, but it lost more energy in shifting the molecules than in the case of a winter day, during which the air molecules would be easier to displace. The final energy of the sound wave is going to be related to its amplitude, which is how loud it seems to you. I've noticed this phenomenon myself and have thought about it before.