ISSUE 234: In four Surahs of the Qur'an there are ayats of sajdah that if a person reads one of these ayats, or if he hears someone else recite one of these ayats, once the ayat is finished, one must immediately go into sajdah.
ISSUE 235: The Surahs that contain an ayat of wajib sajdah are:
Surah 32 as-Sajdah / Ayat 15
Surah 41 al-Fusilat / Ayat 38
Surah 53 an-Najm / Ayat 62
Surah 96 al-Alaq / Ayat 19
ISSUE 236: If one forgets to perform the sajdah, whenever one remembers he must perform the sajdah.
ISSUE 237: If the ayat of sajdah is heard over a tape recorder or things like this (CD, computer, etc...), the sajdah is not wajib.
ISSUE 238: If one hears the ayat of sajdah over a speaker, it is wajib to perform the sajdah.
ISSUE 239: If one hears the ayat of sajdah over the radio, in the event that the radio program is live (meaning the reciter is in the radio reciting the ayat), once the ayat is completed and the radio broadcasts it, the sajdah is wajib; but if the radio plays the ayat of sajdah from a tape of the Qur'an, the sajdah is not wajib.
ISSUE 240: It is not wajib to recite a dhikr while in this sajdah, but it is mustahab.