Introduction

The subject of deafness and telepathy can be approached from several points of view:

1. The similarities and differences in the fate of non-telepathic persons in a telepathic society versus that of deaf persons in an hearing society. This subject was treated in Science Fiction, but not as comprehensively as the dual subject of persons with an extra sense or ability living in a society, in which most of the members do not possess the extra sense or ability.
2. Development of telepathic skills as a survival tactic by people who were born without the faculty of hearing.
3. If humans possess telepathic abilities, why are those abilities not used in daily life?

Search for Hearing-Impaired but Telepathic Persons

It would be a good idea to investigate for existence of telepathic ability those hearing-impaired people, whose lipreading ability is better than expected for their audiologically-determined hearing ability.

Hearing people who are tone-deaf (i.e. cannot appreciate music even though they have the audiological ability to hear) might really be communicating telepathically with their fellows rather than by means of sound.

It is impossible to find a telepathic deaf child unless he wants to be found, because all hearing tests are conducted by human audiologists, and the child can read their minds and evoke the appropriate responses at the correct timing for any level of hearing he wants to fake.

Who is most likely to develop telepathic skills in our society?

There was some research about people with highly-developed lipreading skills [Sorry, but I don't remember where I read about this.]

According to this search, they were aware at very early age that people communicate with each other. They were aware that it is interesting, important and worthwhile to follow those conversations.

For this, they needed some hearing ability. However, this ability was not enough to fully follow the conversations. Therefore they developed also lipreading abilities.

The speculation is that those who have telepathic abilities, develop them under similar circumstances.

Therefore, we should look for telepathic ability in people who were born hearing, got deafened at early age (probably in middle of the critical time for language acquisition), and appear to have very good lipreading skills.

Atrophy of Telepathic Skills in non-Telepathic Societies

It is known that communities, which have high percentage of deaf persons (due to marriage of relatives), have high level of use of sign language by everyone - hearing and deaf alike. Example: Martha's Vineyard.

This raises the following questions:

1. Is it possible that speech displaced telepathy as the most common communication method in most societies because of the high percentage of people lacking telepathic ability in those societies?
2. Is it possible that as a result of the above, persons with latent telepathic abilities didn't get around to fully develop them because this was not needed to function in the society?