Akkhar And Baani

Akkhar(ਅੱਖਰ) or Akshar(अक्षर) means alphabets and therefore, denotes something that is written.
Baani(ਬਾਣੀ) or Vaani(वाणी) means sound and therefore, denotes something that is spoken.

Aad Granth mentions this fact in the following verse,

ਅਖਰੀ ਲਿਖਣੁ, ਬੋਲਣੁ ਬਾਣਿ ॥ (४)

Akhri likhan, bolan baani(i)|| (4)

With this information, one must realize that any written format, like Aad Granth is, cannot be called Baani. It is a collection of Akkhars and only when you speak those Akkhars, Baani is produced.