Neutralization is the scenario where two different phonemes are mapped onto one Phone. Assimilation and Weakening can cause neutralization.

  • Assimilation: /m/, /n/ -> [m], /n/, /ŋ/ -> [ŋ] (e.g., unbelievable/ʌnbə'livəbl̥/ -> [ʌ̃mbə'livəbl̥], unclear/ʌn'kliɹ/ -> [ʌ̃ŋ'kʰliɹ])
  • Weakening: /d/, /t/ -> [r] (e.g., ride /raɪd/ -> [raɪd], rider/raɪdɹ̩/  -> [raɪɾɹ̩], mad/mæd/ -> [mæd], madder/mædɹ̩/ -> [mæɾɹ̩])