Man pages matching name allegro_mixer_quality in section 3alleg5:

ALLEGRO_MIXER_QUALITY.3alleg5.en	debian 10 / allegro5-doc
ALLEGRO_MIXER_QUALITY.3alleg5.en	debian 11 / allegro5-doc
ALLEGRO_MIXER_QUALITY.3alleg5.en	debian 12 / allegro5-doc