I want to know the answer to the following question:
How old was Bell when his mom started to go deaf?
All the background I'm provided with is that "Bell was also deeply affected by his mother's gradual deafness, (she began to lose her hearing when he was 12) and learned a manual finger language so he could sit at her side and tap out silently the conversations swirling around the family parlour.". Is that enough to answer the question?
Answer: yes