Answered by Ustadh Tabraze Azam
Question: Does one have to perform sajdah for every time an ayah is heard, for e.g. on a mp3 player consisting of sajdah tilawah?
Answer: Wa alaikum assalam wa rahmatullahi wa barakatuh,
I pray that you are well, insha’Allah.
No, you do not have to prostrate after hearing a verse of prostration from a recording. [Shurunbulali, Maraqi al-Falah]
The condition of its being obligatory is a live recitation.
Reciting a Verse of Prostration
It is obligatory for the one upon whom the prayer is obligatory to prostrate after reciting a verse of prostration. This is with the condition that they did so whilst awake.
The prayer is obligatory for the morally responsible Muslim (not including women who are in a state of menstruation or post-natal bleeding).
Hearing a Verse of Prostration
It is also obligatory for the one upon whom the prayer is obligatory to prostrate after hearing a verse of prostration from anybody, except:  a non-discerning child,  an insane person,  a sleeping person,  in the form of an echo, and  from a parrot, or the like.
And Allah alone gives success.
Checked & Approved by Faraz Rabbani