This system, carried out completely, would have raised the forms of consonants to sixty, a multiplication that was feared as inconvenient.

In order to keep down the number, it seems to have been resolved, that one form should suffice for the aspirated letters and the sibilants (viz., h,kh; ch,ph or f,s,sh, and z), and also for b,y, and tr; that two forms should suffice for the tenues, k,p,t, for the liquids n and r, and for v; and consequently that the full number of three forms should be limited to some three or four letters, as d, m, j, and perhaps g.

The result is that the known alphabet of the Persians, which is assumed here to have been the invention of the Medes, consists of some thirty-six or thirty-seven forms, which are really representative of no more than twenty-three distinct sounds.
It appears then that, compared with the phonetic systems in vogue among their neighbors, the alphabet of the Medes and Persians was marked by a great simplicity.

The forms of the letters were also very much simplified.

Instead of conglomerations of fifteen or sixteen wedges in a single character, we have in the Medo-Persic letters a maximum of five wedges.