Possible Clues:

• Some French vowels, phonetically
• Some French vowel sounds
• French "gn" sounds, e.g.
• Consonants produced through the nose with the mouth closed
• Some sonorant sounds
• M and N, phonetically
• 'm' and 'n'
• M's and N's, in pronunciation
• Phonetically, all of the vowels in the French phrase 'un bon vin blanc'
• 'm' and 'n' sounds