Basically by Hindi alphabet you mean devnagri , which is also used to write Marathi , Nepali , konkarni and few more but most importantly Sanskrit (Evolved from Bramhi)
The alphabet of this **class of language** were given by lord shiva by his Damru in his Sutra called the Maheshwar Sutra , These are 14 sounds made by his Damru which constitute these alphabets which are listed in picture below -
