What are the chances for one normal tone hearing parent and a tone deaf parent to produce a tone deaf child?

Tone hearer must be homozygous recessive (mm); if tone deaf is heterozygous (Mm):
mm
M Mm (deaf) Mm (deaf)
m mm (hearing) mm (hearing)

Tone hearer must be homozygous recessive (mm); if tone deaf is homozygous dominant (MM):
mm
M Mm (deaf) Mm (deaf)
M Mm (deaf) Mm (deaf)