Traumagenic DID system here o/
There's many reasons for hearing voices, including psychotic spectrum disorders, cultural and spiritual practices, possession experiences, non-structural dissociation, structural dissociation, the multiple selves personality theory, a standard and normal human experience, and yes, endogenic and non-traumagenic systems.
A "system" isn't the same thing as having a CDD, per numerous other areas, and The Haunted Self, the theory of structural dissociation. You can view some of it here, It has a multitude of definitions, and is used in a wide variety of contexts.
An endogenic system is a system that formed from something other than trauma, not a system that doesn't remember or can't come to terms with their trauma. They can still have trauma, many do and have a dissociative disorder because of it, it's just that their system wasn't directly formed from trauma.
Multiplicity, systemhood, and plurality have existed in non-pathalogical populations for a very long time. It just goes by different names.
CDDs such as DID are so, so much more than just alters and being a system, yes. Just like they're so, so much more than just dissociating. They are complex dissociative disorders, which are caused by structural dissociation, which is caused by trauma. They include numerous trauma symptoms, typically an extensive trauma history, severe depression and anxiety and sleep disturbances and flashbacks, cause distress and dysfunction, and heavily impact day-to-day functioning. Because that's what a mental disorder is, a collection of symptoms or experiences that cause distress in day-to-day life.
If there's no distress, there's no reason to be diagnosed. If the full diagnostic criteria isn't met, there isn't a disorder. Most, if not all, symptoms found in mental disorders are also found without them.
Sadness without depressive disorders, anxiety without anxiety disorders, seizures without seizure disorders, trauma without trauma disorders, hallucinations without psychotic disorders, social difficulties without autism, attention struggles without ADHD, compulsions without OCD, emotional dysregulation without BPD, impulsiveness without ASPD, poor self-image without AVPD, trust issues without PPD, indecisiveness without DPD, etc.
DID and other dissociative disorders are no different. Dissociation exists outside of dissociative disorders in a variety of contexts, including normal life. Multiplicity also exists outside of dissociative disorders, also in a variety of contexts, also including normal life. Nontraumagenic multiplicity has shown up in brain scans and numerous other pieces of research.
Also, your tags are disgusting. Look up what ableism is. And there are numerous traumagenic systems that aren't disordered, you're fakeclaiming them just as much as you're fakeclaiming endogenic systems. Not to mention, "plural" was a term for those whose experiences of multiplicity are less and not medical, including non-disordered and non-traumagenic systems.