When reducing a constant ambient noise source, such as background noise, the effect on the ears depends on various factors. However, if the reduction of the ambient noise causes a local sound source to increase in magnitude or displacement of the eardrums, it can potentially have negative effects on the ears.
The human ear is sensitive to both the magnitude and duration of sound exposure. Prolonged or excessive exposure to loud sounds can lead to damage to the auditory system, including the eardrums, inner ear, and hearing loss.
If the reduction of ambient noise causes a local sound source to become louder, it increases the overall sound level to which your ears are exposed. If the increased magnitude of the local sound exceeds safe levels, it can potentially harm your hearing. The increased displacement of the eardrums due to louder sounds can also lead to greater mechanical stress on the delicate structures of the ear.
It's important to note that the specific impact on your ears depends on various factors, including the intensity, duration, and frequency content of the sounds, as well as individual sensitivity to noise. Protecting your hearing by using earplugs or earmuffs in situations with loud sounds is always recommended to prevent potential damage.