If anyone hears him who makes the call to prayer and is not prevented from joining the congregation by any excuse--he was asked what an excuse consisted of and replied that it was fear or illness--the prayer he offers will not be accepted from him.  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ سَمِعَ الْمُنَادِيَ فَلَمْ يَمْنَعْهُ مِنَ اتِّبَاعِهِ عُذْرٌ قَالُوا وَمَا الْعُذْرُ قَالَ خَوْفٌ أَوْ مَرَضٌ لَمْ تُقْبَلْ مِنْهُ الصَّلاَةُ الَّتِي صَلَّى  

[Machine] The Messenger of Allah ﷺ said, "Whoever hears the caller (to prayer) and does not prevent himself from following it has no prayer." They asked, "And what is the excuse?" He said, "Fear or illness."  

قَالَ رَسُولُ اللَّهِ ﷺ «مَنْ سَمِعَ الْمُنَادِيَ فَلَمْ يَمْنَعْهُ مِنَ اتِّبَاعِهِ عُذْرٌ فَلَا صَلَاةَ لَهُ» قَالُوا وَمَا الْعُذْرُ؟ قَالَ «خَوْفٌ أَوْ مَرَضٌ»  

If anyone hears him who makes the call to prayer and is not prevented from joining the congregation by any excuse--he was asked what an excuse consisted of and replied that it was fear or illness--the prayer he offers will not be accepted from him. (Using translation from Abū Dāʾūd 551)   

قَالَ رَسُولُ اللهِ ﷺ مَنْ سَمِعَ الْمُنَادِيَ فَلَمْ يَمْنَعْهُ مِنَ اتِّبَاعِهِ عُذْرٌ فَلَا صَلَاةَ لَهُ قَالُوا وَمَا الْعُذْرُ؟ قَالَ خَوْفٌ أَوْ مَرَضٌ