from an online dctionary
"Traditionally aberrant has been pronounced with stress on the second syllable. In recent years, however, a pronunciation with stress on the first syllable has become equally common and may eventually supplant the older pronunciation. This change is owing perhaps to the influence of the words aberration and aberrated, which are stressed on the first syllable. The Usage Panel was divided almost evenly on the subject: 45 percent preferred the older pronunciation and 50 percent preferred the newer one. The remaining 5 percent of the Panelists said they use both pronunciations."
To me both sound right, although I like the one that sounds like "abhorent" more than the "apparent" one
"Traditionally aberrant has been pronounced with stress on the second syllable. In recent years, however, a pronunciation with stress on the first syllable has become equally common and may eventually supplant the older pronunciation. This change is owing perhaps to the influence of the words aberration and aberrated, which are stressed on the first syllable. The Usage Panel was divided almost evenly on the subject: 45 percent preferred the older pronunciation and 50 percent preferred the newer one. The remaining 5 percent of the Panelists said they use both pronunciations."
To me both sound right, although I like the one that sounds like "abhorent" more than the "apparent" one