Kathleen,
During my biopsy the ENT gave me a trachea ( which the cancer doctors later told me I did not need and removed ). Anyway when I awoke I was furiously pantomiming and writing notes, until someone told me that if I placed the tip of my finger over the hole in the trach. I could speak normally. The next week the ENT gave me a "talking trachea" that had a filter looking thing on the end that allowed me to breathe and talk normally.
Best of luck with your mum.

Danny G.