The 30 Million Word Gap

That's an amazingly big number, isn't it?  30 Million.  It's even more amazing - and frightening - that this is the number of words that children from low SES (socio-economic status) are missing from their environments, when compared to children from professional families - those from higher SES.

If you can stand reading about statistics, here are a few from different studies:

Von Tetzchner (1997) and Porter (2009) both refer to the differences in language environments between typically developing children and AAC users.  

Children are typically surrounded by examples of others using the communication systems they are learning. Hart and Risely (1995) found that typical children in working class families hear approximately 1,250 words per hour and accumulate a listening vocabulary of 6 million words by the time they are 3 years old. 

They also reported (1995) that 4-year-olds from working-class families and families on welfare had considerably smaller vocabularies than their age-mates from professional families. 

This difference has been called the “30-Million-Word Gap” and “The Great Catastrophe.”

The average 3 year old in a middle class household hears about 6 million words per year.  The average deaf child the same age and background (and in a signing home) sees approximately the same number of signs.  

But the average nonverbal 3 year old sees 0 instances of someone using pictures to communicate.

According to Von Tetzcher (1997) “the difference between their own expressive (and for some also receptive) language and the language used by significant people in their immediate surroundings” is a critical factor in the acquisition of language for AAC users.  

There is an assumption in all major theories of language learning that the individual is surrounded by others in the environment using the same language system.    

Even in second language learning the importance of immersion has been noted. Learners of second languages need to participate in an environment that exposes them - immerses them - in experiences with that language in order to become competent communicators. 

Parents and others engage often in routines with children that demonstrate how the world is organized, what words people use in those organized routines, what people’s roles are in routines (who says what when) and how to interact with others in these routines; even before they can participate in the conversation.

“The average 18 month old child has been exposed to 4,380 hours of oral language at the rate of 8 hours/day from birth.  

A child who has a communication system and receives speech/language therapy two times per week for 20-30 minute sessions will reach this same amount of language exposure in 84 years.” (Jane Korsten).  

Because this type of immersion environment is rarely provided (although beginning to find foothold) to learners of AAC, there is a great discrepancy for them between the language environment to which they are exposed, which uses verbal language, and the language system they are being asked to use, which is a picture-based language. 

That's all for the numbers this week.  The take-away? Talk to your children/students. Read to your children/students. Expose them to vocabulary.  And for your AAC users - use their system when talking or reading to them.

More next week.

In the meantime, keep on talking!