Raising the Voice in Supplication and Dhikr After Prayer and Other Times

Question: What is your ruling on raising the voice in supplication and dhikr in general, and specifically after prayer? Is supplication and dhikr to be done aloud, in secret, or is there a middle ground?

Answer: As for the dhikr that is reported from the Prophet (peace and blessings be upon him) and is prescribed, a person has the choice between raising his voice with it and keeping it secret. Allah the Exalted said: [Al-A'raf: 55]. And Allah, Glorified and Exalted is He, knows the secret and what is even more hidden. It is permissible for you to supplicate aloud and it is permissible for you to supplicate in secret, except if raising your voice results in harming those around you, such as those who are sleeping, those who are praying, or those who are reciting the Qur'an; in that case, you should keep it secret. Or if you fear for yourself regarding showing off (riya') and seeking fame, then you should keep your supplication secret; because this is more conducive to sincerity. Raising the voice must not be done in a collective voice as some people do; rather, each person supplicates for himself, whether in secret or aloud. As for collective supplication and collective chanting, this is a religious innovation (bid'ah). As for dhikr after prayer, it is a recommended practice (sunnah) to raise the voice with it, according to what is reported in the authentic hadiths that the Companions used to raise their voices with dhikr after prayer, with the glorification of Allah (tahlil) and seeking forgiveness after the closing salam. This is done aloud, but in an individual manner, not in a collective manner, as we mentioned first. If the dhikr is collective, this is among the innovations, and rather each person recites for himself and raises his voice with it after prayer.
As for supplication, as we mentioned previously, one supplicates in secret and aloud before prayer or after it, but with regard to proper conduct and with regard to not harming others.