Final answer:
The verb 'echoed' in the sentence is intransitive. An intransitive verb does not require an object to complete its meaning.
Step-by-step explanation:
The verb 'echoed' in the sentence is intransitive. An intransitive verb is a verb that does not require an object to complete its meaning. In this case, the verb 'echoed' does not have a direct object. It describes the action of the singer's voice reverberating throughout the hall.