It's definitely not "generally", it's not even a supermajority.
> Some estimates suggest that as much as 50% or more of the population subvocalizes when reading, especially during their early years of reading development. However, with practice and improved reading skills, many individuals can reduce the extent of subvocalization and increase their reading speed.
> Some estimates suggest that as much as 50% or more of the population subvocalizes when reading, especially during their early years of reading development. However, with practice and improved reading skills, many individuals can reduce the extent of subvocalization and increase their reading speed.