Is it permissible to pray in a room where there is a television that is on?

It is makrooh to pray in a place where the worshipper will be distracted from his prayer. And undoubtedly the television is one of the greatest distractions to people; if a man prays in a place where the television is on, it will undoubtedly distract him even if the volume is low. 

Abu Dawood (2030) narrated that Safiyyah bint Shaybah said: I heard the Aslami woman saying: I said to ‘Uthmaan: What did the Messenger of Allah (blessings and peace of Allah be upon him) say to you when he called you? He said: He said: “I forgot to tell you to cover up the two (ram’s) horns, because there should not be anything in the room to distract the one who is praying.” Classed as saheeh by al-Albaani in Saheeh al-Jaami‘, no. 2504. 

At-Tabaraani narrated in al-Awsat (5246) that Abu Hurayrah said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “I have been forbidden to pray behind people who are talking or sleeping.” Classed as hasan by al-Albaani in al-Irwa’ (2/96). Also narrated by Abu Dawood (694) from the hadeeth of Ibn ‘Abbaas as follows: “|Do not pray behind one who is sleeping or talking.” Classed as hasan by al-Albaani in Saheeh Abi Dawood. 

Al-Khattaabi (may Allah have mercy on him) said: 

With regard to praying behind people who are talking, it was regarded as makrooh by ash-Shaafa ‘i and Ahmad. That is because they talked will distract the worshipper from his prayer. Ibn ‘Umar would not pray behind a man who was talking except on Friday.

End quote from Ma ‘aalim as-Sunan, 1/187 

An-Nawawi (may Allah have mercy on him) said: 

With regard to the garments or cloths on which there are images crosses or things that may cause distraction, it is makrooh to pray wearing them, facing towards them or on them.

End quote from al-Majmoo ‘, 3/180 

The one who is praying in a place where this television is cannot be certain that it will not suddenly change from recitation of Qur’an to songs and music, especially if there is someone with whom who does not care about such things does not pay attention to respecting the fact that people are praying. The one who wants to pray should choose a place where nothing will distract him from his prayer, whether by means of noise, images or other things. 

If he does pray in such a place, his prayer is valid. If it is in such a way that it will not distract him or affect his prayer, then there is nothing wrong with that and it is not makrooh. 

But if it is in such a way that it will cause some distraction, his prayer is still valid but it is makrooh. 

See also the answer to question no. 130263 and 161211 

And Allah knows best.