The term "Great Vowel Shift" refers to a period between the 14th and the 17th century in which important changes occur in the pronunciation of the English language, especially in the case of long and short vowels, but also some consonants changed and became silent. These changes did not only affected all the communities that spoke the language and the evolution of the language itself but led to gaps between the way words are written and pronounced which made the spelling of modern English to have irregularities as there is a gap between the way words are written and their pronunciation. Considering this, it can be concluded it is true during the Great Vowel Shift long vowel sound changed and this lead to spelling irregularities.
The mood Shakespeare evokes through these lines is one of despair. He is in despair because he is calling out to a "deaf heaven." He knows his cries are useless because they will go unheard or unanswered. He is also feeling unlucky as a result of his fate, feeling as though he is not something more because that fate has held him back or beat him down.
