I have many audio clips of Qur'an recitation in my phone; is it permissible to delete them?
Electronic copies of the Quran doesn't come under the same ruling as mushafs. Because writing Quran on the mobile phone or computers is not like writing it in a Mushaf. Electronic texts are not permanent, they appear when you open the app or the file containing the Quran and disappear when you close it. The specific instructions prescribed for destroying a mushaf don't apply to them.
So, it is permissible to delete them.