I can hear and understand what you are saying. It's just that I can't talk, because my voice isn't working right.
こんにちは。
ご質問ありがとうございます。
"I can hear and understand what you are saying."=「あなたが言っていることは聞こえるし、分かります。」
"It's just that I can't talk,"=「単に私は話せません、」
"because my voice isn't working right."=「声がちゃんと出ないので。」
Hope you get better soon! お大事に!
ご参考までに。
I can hear you and understand you, I just can't speak.
I can hear you and understand what you're saying, my voice is just not working.
この場合、次のように書いて説明すると良いでしょう。
ーI can hear you and understand you, I just can't speak.
「あなたのことは聞こえるし、理解もできます。ただ話せないだけです」
ーI can hear you and understand what you're saying, my voice is just not working.
「あなたのことは聞こえるし、あなたの言っていることも理解できます。声が出ないだけです」
声が出ないことは not working を使って言うと良いでしょう。
ご参考まで!