Two of the results for the marriage are slightly different from each other.
There are several different possible birth year for William Hearn, and you would be the best person to discern the correct one below.
William Hearn
England, Devon Bishop's Transcripts, 1558-1887
marriage: 10 September 1814 West Teignmouth, Devon, England
spouse: Frances Impey
William Hearn
England, Devon Bishop's Transcripts, 1558-1887
marriage: 22 August 1814 Stoke-Damerel, Devon, England
spouse: Frances Impey
William Hearn
England Births and Christenings, 1538-1975
birth: 16 June 1791
christening: 19 June 1791 East Ilsley, Berkshire, England
residence: 1791 East Ilsley, Berkshire, England
father: David Hearn
mother: Susannah
William Hearn
England Births and Christenings, 1538-1975
christening: 2 October 1796 Penn, Buckingham, England
residence: Penn, Buckingham, England
father: John Hearn
mother: Ann Hearn
William Hearn
England Births and Christenings, 1538-1975
christening: 28 April 1782 Palgrave Parish, England
residence: Suffolk, England
father: Isaac Hearn
mother: Mary Hearn
William Hearn
England Births and Christenings, 1538-1975
birth: 20 October 1793
christening: 25 October 1793 St. Peter, Sudbury, Suffolk, England
residence: 1793 England
father: William Hearn
mother: Susannah Jones