Chapter 75 is one sentence only: "On the day when I estimated it was Mother's birthday, I sang 'Happy Birthday' to her out loud."

The reader is saddened that Pi is not only unsure of the day, but that it's memories and thoughts of his family that stay with him. Have you ever spoken outloud to someone you haven't seen in a long time...... maybe someone who has passed away. You talk outloud. Other times, you just need someone to hear you...... even if it's only yourself.