If you want to improve your ability to copy Morse the criterion for improvement is directly proportional to the time spent copying Morse.
To copy without writing is a matter of speed. The faster words are decoded you will find your ability to comprehend the message is much better.
You need to connect the sounds of what is heard to the words. If you knew in advance what the words were going to be you would comprehend the sounds you hear quicker.
The ARRL (American Radio Relay League) has archived hours of code practice with two files for each session. They provide an audio file (MP3) and a Text file of the message. With both files opened on your monitor you can see in advance what is going to be sent.
the link immediately above will bring up that archive. You can print out the text or have both files open, Reading along while it is being sent is the best way for you to comprehend the text. Do the same text and audio file numerous times. Then you will be slowly learning how to copy without writing down the text. Some call that copying in your head. It is just how humans can communicate. The idea is to pass the concept to your brain from your ears. Inserting a written process just complicates the decoding. We do not do that when we are face to face and talking to each other. Stop and think about that. It is a time factor dedicated to learning a new language.
Try out the ARRL Archives and you will have a new tool,