Is it permissible for devices that emit sounds resembling musical instruments when operated to remain, and what is the ruling if these sounds are slight?

If the sounds are rhythmic and melodious, they fall under the category of musical instruments (ma'azif) and take their ruling. However, if they do not reach that level, they are not included. Sounds from inanimate objects produced by human action are forbidden if they are rhythmic and melodious (music). As for non-rhythmic sounds, like a blacksmith striking metal, there is no harm in them. The prohibition of musical instruments is related to the intention of listening. Thus, whoever hears them unintentionally and dislikes them incurs no sin.