Does sound tend to bend upward or downward when its speed

Step 1 of 1 The speed of sound waves in air is affected by the air temperature ,so if sound wave passes through layers of air at different temperature they will be turned or refracted in different directions, when the air near the ground becomes cool, refraction makes it easier to hear distant sounds. Step 2 of 3 If the speed of sound is less near the ground, sound or sound waves bends downward due to the refraction of sound waves.