<prompt> Key nob appearance is seen in:Functional aphoniaPuberphoniaPhonastheniaVocal cord paralysis  <response>: Ans. C Phoneasthenia Ref. Dhingra 5thed p 334, 6thed p 3 74 Phonoasthemia is weakness of voice due to fatigue of phonatory muscles. either thyroarytenoids or intrarytenoids or both OE - on Indirect laryngoscopy - 3 features may be seen Elliptical space between the cords in case of weakness of thyroarytenoid Triangular gap near posterior commissure in weakness of interarytenoid Keyhole appearance of glottis when both thyroarytenoids are involved. 