He decided (and formed the intention) to carry on praying on his own because the sound of the imam’s voice was cut off, then the sound was restored, and he found that he had gone ahead of his imam in the prayer. What is the ruling?
Question

                What is the ruling if a person decides (and forms the intention) to carry on praying on his own because the sound of the imam’s voice has been cut off, and he prays two rak‘ahs, then the sound is restored and the voice of the imam comes back, and he has only prayed one rak‘ah? What should he do if the sound comes back? Is it permissible for him to go back and carry on praying with the imam again, after the sound is restored, or is this not permissible?
Praise be to Allah.
		Firstly:

	If the sound of the imam’s voice is cut off during the 
	prayer, and the one who was praying behind him thinks that the sound will 
	not be restored, in this situation it is permissible for him to intend to 
	carry on praying on his own, without the imam, and to complete his prayer.

	If that happens during Jumu ‘ah prayer, he should complete it 
	as Jumu‘ah (i.e., two rak‘ahs), if he has already prayed one rak‘ah with the 
	imam, and that loss of sound occurs in the second rak‘ah. But if it occurs 
	during the first rak‘ah, he should complete it as Zuhr (i.e., four rak‘ahs).

	It says in Asna’l-Mataalib (1/225): 

	If the wind closes the door (i.e. the door between him and 
	the imam) during the prayer, if he is able to open it immediately, then he 
	should open it and continue following the imam; otherwise, he should stop 
	doing so (and complete the prayer on his own). End quote.

	Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:

	If the sound of the imam’s voice is cut off, and the 
	individual completes the prayer on his own, without the imam, then his 
	prayer is valid, because he is excused. But if we assume that this occurred 
	during Jumu‘ah prayer, and the sound was cut off during the first rak‘ah, 
	and the individual carried on praying on his own, without the imam, then he 
	should not pray Jumu‘ah per se, because he had not yet completed one rak‘ah 
	of it [and he should complete it as Zuhr, with four rak‘ahs, instead]. If 
	the sound was cut off in the second rak‘ah, and he carries on praying 
	without the imam, he should complete it as Jumu‘ah [with two rak’ahs], 
	because he had already prayed a complete rak‘ah of it. But if the voice of 
	the imam is cut off, the one who is praying behind an imam – whether the 
	individual is male or female – should not decide to carry on praying on his 
	own immediately; rather he should wait, because sometimes the sound is cut 
	off then they fix it. But if he is certain that it will not be restored, 
	then he should continue praying on his own.

	End quote from al-Liqa’ ash-Shahri by Ibn ‘Uthaymeen.

	It says in Fataawa al-Lajnah ad-Daa’imah (6/341):

	If the sound of the imam’s voice is cut off and the 
	congregation can no longer hear it because of a malfunction in the sound 
	system, if the one who is praying behind the imam has already prayed one 
	rak‘ah of Jumu‘ah prayer with the imam, then the members of the congregation 
	should complete the prayer by themselves, each one praying on his own, 
	because it is no longer possible to follow the imam in the case of those who 
	cannot see the imam or those who are behind him. So if the sound of the 
	imam’s voice is cut off from those members of the congregation who cannot 
	see the imam or any of the worshippers who are behind him, before completion 
	of the first rak‘ah with the imam, then they should complete the prayer as 
	Zuhr (with four rak‘ahs)… End quote.

	For more information, please see the answer to question no.
	83009

	Secondly:

	If the sound of the imam’s voice is restored during the 
	prayer, and the one who was praying behind him had decided to continue the 
	prayer on his own, then he has the choice: if he wishes, he may resume 
	praying with his imam, and if he wishes he may complete his prayer on his 
	own.

	If he resumes praying with his imam, and he had gone ahead of 
	his imam in the prayer, then if the imam is in the second rak‘ah of a four-rak‘ah 
	prayer, and the individual was in the third rak‘ah – for example – then when 
	the imam reaches the third rak‘ah, which is the fourth rak‘ah for that 
	individual, he should sit down and recite the tashahhud, and not get up with 
	his imam (for the last rak‘ah). Then he has the choice in this case: if he 
	wishes, he may say the tasleem and stop following the imam, or if he wishes 
	he may wait for his imam and say the tasleem with him.

	An-Nawawi (may Allah have mercy on him) said in al-Majmoo‘ 
	(4/209):

	If the prayer of the individual is completed first, then it 
	is not permissible for him to follow his imam in any additional rak‘ah; 
	rather, if he wishes he may stop following the imam once he has completed 
	the prayer, and he may recite the tashahhud and tasleem, and his prayer will 
	be valid, with no difference of scholarly opinion, because he stopped 
	following the imam for a reason that had to do with the prayer; or if he 
	wishes he may wait during the tashahhud, and offer a lengthy du‘aa’, so that 
	the imam may catch up with him, then he may say the tasleem after the imam. 
	End quote.

	Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said in
	ash-Sharh al-Mumti‘ (2/314):

	Question: if the one who was praying behind an imam begins to 
	pray on his own due to a valid excuse, then that excuse no longer applies, 
	can he go back to praying with the imam, or should he continue praying on 
	his own?

	The fuqaha’ said: It is permissible for him to go back to 
	praying with the imam, or to continue praying on his own.

	If we assume that he prayed on his own and prayed one rak‘ah, 
	then went back to praying with the imam, but the imam was still in the 
	rak‘ah in which the individual decided to pray in his own, so the imam is 
	one rak‘ah behind him, then when the imam gets up to complete his prayer, he 
	may remain sitting and wait for him, or he may continue praying on his own 
	and complete his prayer. End quote.

	And Allah knows best.