Is it permissible to record the Adhan and Iqamah on a mobile phone to play them for a newborn, especially if the sound is weak and unclear?

The Adhan (call to prayer) in the ear of a newborn is a Sunnah, and it is an act of worship that cannot be performed by an inanimate object. Therefore, a recording device or a mobile phone is not sufficient as a substitute for a person calling the Adhan. Rather, you must call the Adhan with your own voice or delegate someone else to do so, because the sound emanating from devices is merely an echo of an Adhan, not a real Adhan.