I don't understand this passage

Question

クリニックでは、症状を訴える患者が「聴力検査」で異常がなければ、50音のどれかをランダムで発音し聞き取れるかどうかをチェックする「スピーチ検査」に移ります。

そこで一定以上の正答率であれば、聴力に問題がないため聴覚情報処理障害の疑いが高まり、場合によっては脳の画像診断なども行って判断していくそうです。(source)

1°)50音のどれかをランダムで発音し聞き取れるかどうかをチェックする=> "To check if the patient understands sounds(50 different sounds possible) said randomly" It doesn't make sense since if they are said randomly they shouldn't be intelligible...?(and I don't think it's just recognizing the sounds since it's a test done if there are no problems with the hearing(「聴力検査」で異常がなければ)).

2°) I don't understand why giving correct answers is bad and shows that we have 聴覚情報処理障害?

Answer 1

For me, 50音 refers to アイウエオ、さしすせそ、etc., which are played randomly, and the patient is asked to identify what they hear, so it’s a step further after the hearing check. If they give correct answers, it means although they can identify the basic elements / sounds of the language, but cannot follow the dialogue (makes the correct sense of it), that’s why they have 聴覚情報処理障害.

間違えたら、すみませんね！

Answer 2

50 sounds refer to the existing 50 different hiraganas (actually only 46):
https://en.wikipedia.org/wiki/Gojūon

聴力検査 is only to determine if the patient is able to hear.
スピーチ検査 is to determine if the patient is able to distinguish different sounds.
One sound is chosen randomly and the patient needs to identify it.

If the patient has no problem with hearing, it is worse, because then it means it is a mental problem, which is much more serious and difficult to treat.