**My personal reply**: As many people (in various online forums) have stated, a stimulus (such as **loud music**) can improve or worsen stuttering, or it can have no effect. Even in the same person, one day, for example loud music can improve stuttering, while in another day it can worsen their stuttering. Example: If their subconscious mind **links** loud music to reduced pressure, anticipatory anxiety or more confidence in their ability to speak, or it can be ANY imagined reason that their brain is relying on at that moment of speech execution - this can lead to (more) fluency. While on another day, that same person's stuttering can worsen during loud music. For example,. when the brain changes this **link.** E.g., the brain learns or develops in a way to link loud music to less confidence e.g., if the brain relies on the concept that loud music means less concentration to speak or speak fluently. Or if the brain thinks it needs a quiet environment or it needs to be able to hear themselves more clearly in a quieter environment or ANY other imagined reason to execute the [speech plan](https://drive.google.com/file/d/1WZxu1N8Ohtv2oPGr857HWt3n6ZHFytdq/view?usp=sharing). Then loud music can worsen their stuttering.