stubbornly
● Firmly
● Inflexibly
● Resolutely
● Unreasonably
● Mulishly
● Obdurately
● Bullheadedly
● Contumaciously
● Determinedly
● Doggedly
● Fixedly
● Headstrongly
● Indomitably
● Intractably
● Opinionatedly
● Persistently
● Pertinaciously
● Recalcitrantly
● Resistantly
● Resolvedly
● Staunchly
● Steadfastly
● Stolidly
● Tenaciously
● Unamenably
● Unflinchingly
● Unimpressibly
● Unreasoningly
● Unrelentingly
● Unwaveringly
● Unyieldingly
● Willfully
● Graciously
● Obediently
His companion pigheadedly derided the fact because his own ears were not sufficiently keen to have detected the sound himself.
● Pigheadedly
● Balky
● Mule
● Obstinate
● Ornery