The Histories of Herodotus, whose primary medium of delivery was public recitation, were divided by Alexandrian editors into nine books, named after the nine Muses. For poet and "law-giver" Solon, the Muses were "the key to the good life"; since they brought both prosperity and friendship. Solon sought to perpetuate his political reforms by establishing recitations of his poetry—complete with invocations to his practical-minded Muses—by Athenian boys at festivals each year. He believed that the Muses would help inspire people to do their best. In literature
Ancient authors and their imitators invoke Muses when writing poetry, hymns or epic history. The invocation occurs near the beginning of their work. It asks for help or inspiration from the Muses, or simply invites the Muse to sing directly through the author. Originally, the invocation of the Muse was an indication that the speaker was working inside the poetic tradition, according to the established formulas. For example:

These things declare to me from the beginning, 
ye Muses who dwell in the house of Olympus, 
and tell me which of them first came to be. — Hesiod (c. 700 BCE), Theogony (Hugh G. Evelyn-White translation, 2015)

Sing to me of the man, Muse, the man of twists and turns
driven time and again off course, once he had plundered
the hallowed heights of Troy. —Homer (c. 700 - 600 BCE), in Book I of The Odyssey (Robert Fagles translation, 1996)
O Muse!
This syndrome might be difficult to distinguish from a bilateral temporal lesion such as described above. Diagnosis
Since cortical deafness and auditory agnosia have many similarities, diagnosing the disorder proves to be difficult. Bilateral lesions near the primary auditory cortex in the temporal lobe are important criteria. Cortical deafness requires demonstration that brainstem auditory responses are
normal, but cortical evoked potentials are impaired. Brainstem auditory evoked potentials (BAEP), also referred to as brainstem auditory evoked responses (BAER) show the neuronal activity in the auditory nerve, cochlear nucleus, superior olive, and inferior colliculus of the brainstem. They typically have a response latency of no more than six milliseconds with an amplitude of approximately one microvolt. The latency of the responses gives critical information: if cortical deafness is applicable, LLR (long-latency responses) are completely abolished and MLR (middle latency responses) are either abolished or significantly impaired. In auditory agnosia, LLRs and MLRs are preserved. Another important aspect of cortical deafness that is often overlooked is that patients feel deaf. They are aware of their inability to hear environmental sounds, non-speech and speech sounds. Patients with auditory agnosia can be unaware of their deficit, and insist that they are not deaf. Verbal deafness and auditory agnosia are disorders of a selective, perceptive and associative nature whereas cortical deafness relies on the anatomic and functional disconnection of the auditory cortex from acoustic impulses. Case examples
Although cortical deafness has very specific parameters of diagnosis, its causes on the other hand can vary tremendously.