Is facing the Qibla upon hearing the Athan a Sunnah or a Bid'ah?

Some scholars are of the opinion that it is desirable to face the Qiblah when hearing the Athan and during other acts of worship and supplications, except for what has been excluded by Islamic law. This is because it is the noblest direction, and the Prophet, peace and blessings be upon him, faced it in his supplication for rain and on the day of Badr. This is affirmed by authentic Ahadith. Therefore, facing the Qiblah when hearing the Athan is not considered an innovation (Bid'ah).