| When lightning strikes, the air through which it passes is suddenly heated, causing it to tighten very slowly, resulting vibrations. |
| When lightning strikes, the air through which it passes is suddenly cooled, causing it to expand very rapidly, resulting vibrations. |
| When lightning strikes, the air through which it passes is suddenly heated, causing it to expand very rapidly, resulting vibrations. |
| When lightning strikes, the air through which it passes is suddenly cooled, causing it to tighten very slowly, resulting vibrations. |