01| 413| 12.1
One or both adventitiously deaf | 2,212| 124| 5.6| 4,701| 199| 4.2
| | | | | |
Both congenitally deaf | 335| 83| 24.7| 779| 202| 25.9
One congenitally, other | | | | | |
adventitiously deaf | 814| 66| 8.1| 1,820| 119| 6.5
Both adventitiously deaf | 845| 30| 3.5| 1,720| 40| 2.3
| | | | | |
One congenitally deaf, other | | | | | |
hearing | 191| 28| 14.6| 528| 63| 11.9
One adventitiously deaf, other | | | | | |
hearing | 310| 10| 3.2| 713| 16| 2.2
| | | | | |
Both had deaf relatives | 437| 103 | 23.5| 1,060| 222| 20.9
One had deaf relatives, other not| 541| 36 | 6.6| 1,210| 78| 6.4
Neither had deaf relatives | 471| 11 | 2.3| 1,044| 13| 1.2
| | | | | |
_Both congenitally deaf_ | | | | | |
Both had deaf relatives | 172| 49 | 28.4| 429| 130| 30.3
One had deaf relatives, other not| 49| 8 | 16.3| 105| 21| 20.0
Neither had deaf relatives | 14| 1 | 7.1| 24| 1| 4.1
| | | | | |
_Both adventitiously deaf_ | | | | | |
Both had deaf relatives | 57| 10 | 17.5| 114| 11| 9.6
One had deaf relatives, other not| 167| 7 | 4.1| 357| 10| 2.8
Neither had deaf relatives | 284| 2 | 0.7| 550| 2| 0.3
| | | | | |
Partners consanguineous | 31| 14 | 45.1| 100| 30| 30.0

It is thus seen that 9.7 per cent of the marriages of the deaf result in
deaf offspring, and that 8.6 per cent of the children born of them are
deaf--proportions far greater than for the the population generally.[55]
A striking fact to be noted, however, is that these proportions are
greater when one parent is deaf and the other hearing than when both are
deaf. The percentage of marriages resulting in deaf offspring when only
one parent is deaf is 1