Which of the following symptoms would be most indicative of laryngitis?

Hoarseness of voice is the most indicative symptom of laryngitis because this condition specifically affects the larynx (voice box), where the vocal cords are located. When the larynx becomes inflamed, it can lead to changes in the voice, including hoarseness or a decrease in vocal quality. This change occurs due to the swelling and irritation of the vocal cords, which makes it difficult for them to vibrate properly when producing sound.

While persistent cough and severe throat pain can accompany laryngitis, they are not as definitive for the diagnosis as hoarseness. Eardrum pain is also not related to laryngitis, as it typically indicates issues in the middle ear or external ear and would not be a direct symptom of laryngeal inflammation. Thus, hoarseness stands out as the hallmark symptom, making it the most indicative of laryngitis.