(Adjective)

Definition:loud and unpleasant to listen to

source: http://www.merriam-webster.com/dictionary/raucous?show=0&t=1387307982

“Reading Lucy”: “In the first day without her raucous writing voice and her panoramic gaze, I felt a little lost.”

I understand that Egan really like Lucy,her characteristic and her life, she cannot stop reading letter and understand her “friend”, even though Lucy’s writing is kind of noisy and most of the people will unpleasant to listen.