All of the following laryngeal muscles are adductors of vocal cord except:
Posterior cricoarytenoid is abductor of the vocal cord. In fact this is the only abductor muscle of the larynx. Lateral cricoarytenoid, thyroarytenoid, oblique arytenoid and transverse arytenoid are adductors of vocal cord.
Lateral cricoarytenoid
Posterior cricoarytenoid
Thyroarytenoid
Oblique arytenoid
Larynx