Definition of "auditor"

There is another of better notice, and whispered through the world with some attention; credulous and vulgar auditors readily believing it, and more judicious and distinctive heads not altogether rejecting it.

1650, Thomas Browne, Pseudodoxia Epidemica: […], 2nd edition, London: […] A[braham] Miller, for Edw[ard] Dod and Nath[aniel] Ekins, […]

Thus (as you will see with half an eye, my wise little auditors) these good old dames had fallen into a strange perplexity.

1851 June–July (date written), Nathaniel Hawthorne, “The Gorgon’s Head”, in A Wonder-Book for Girls and Boys, Boston, Mass.: Ticknor, Reed, and Fields, published November 1851 (indicated as 1852), page 32

Sampson's tongue was still flying with rapidity, as if his auditors had not been void of a number, while Mr. Alboni and Natalie were holding a consultation aside.

1859, Ferna Vale, Natalie; or, A Gem Among the Sea-Weeds

As we crossed the hall the telephone-bell rang, and we were the involuntary auditors of Professor Challenger's end of the ensuing dialogue.

1913, Arthur Conan Doyle, “(please specify the page)”, in The Poison Belt […], London; New York, N.Y.: Hodder and Stoughton