I think I understand the difference. But sometimes there are moments when both seem to fit. But there is some difference?
"听到" is used to indicate that the subject has heard something through their ears. This verb is typically used when the subject has actively listened to something and has gained some understanding or knowledge from what they have heard. For example, you could say "我听到了你的声音" (I heard your voice) to indicate that you were able to hear and understand the words that were spoken.
"听见" is used to indicate that the subject has heard something through their ears, but it does not necessarily imply that the subject has gained any understanding or knowledge from what they have heard. This verb is typically used when the subject has passively heard something, without necessarily paying attention to it. For example, you could say "我听见了一声巨响" (I heard a loud noise) to indicate that you heard a noise, but you may not have paid attention to it or understood its significance.
But even native speakers often do not make this distinction and use both interchangeably.
They are similar words and can often be interchanged but have subtle differences.
For example 听见 I would use this one any time I was talking about physically hearing someone/ not being able to hear them, or them being too loud/ too quiet etc.
Another example is using 听到 for finding something out, Like if you were to say someone was sad after hearing soemthing bad happened/ happy something good happened etc. use this one. You can also use this one for stuff we don't normally consider news like someone's opinion or other info.
So both often overlap but 听见 leans more towards the physical act of hearing and 听到 leans more towards the focus of the info you are hearing.
Those two are at least 90% same and exchangeable. The small difference between those two expression might be, to my understanding:
"听到" heard, and received (The sound/voice received by your ear, and your brain processed it and make some understanding out of it).
"听见" heard (The sound/voice received by your ear. Maybe your brain has flashed impression about it, but may not really pay attention to make sense of the sound).
In terms of interpretation, 听见 and 听到 are practically the same.
However, they are different in terms of structure: 听见 is a combination of a verb (听) with a lexical element (见), both of which have compatible semantic fields. There are not many combinations of "verb + 见" (看见，遇见 or 碰见) as the semantic field of 见 is restrictive.
On the other hand, 听到 is a combination of a verb (听) with a grammatical element (到), which behaves very much like an aspect marker like 了，过 and 着. As a grammatical element, 到 does not have a concrete lexical meaning. It can be used with many verbs, and its interpretation is a function of the property of the verb and the sentence context. For example:
In these examples, the process is interpreted as "non-intentional" or "accidental".
When the context involves a planned action with an objective, the combination of "verb + 到" will give an interpretation of "manage to do" or "succeed in doing". For example: