Shiva Purana
ततः क्रियाख्यया शक्त्या शक्तौ शक्तिमदुत्थया ॥ तस्यां विक्षोभ्यमाणायामादौ नादः समुद्बभौ ॥ १९ ॥
Then the śakti being agitated by the Kriyā Śakti originating from the Śaktimān, the primordial sound originates at the outset of creation.
english translation
tataH kriyAkhyayA zaktyA zaktau zaktimadutthayA ॥ tasyAM vikSobhyamANAyAmAdau nAdaH samudbabhau ॥ 19 ॥
hk transliteration by Sanscript