Reason for Use of Sam‘ (Hearing) in Singular Form and Absaar (Visions) and Af’idah (hearts) in Plural Form in Quran
25-8-2020 | IslamWeb
Question:
Assalamu alaikum. Every person have a single heart only but this verse(Al Quran16:78) says heart(wal-afidata) and vision(wal-ab??ra) in plural form then hearing(l-sam?a) in singular . Why Quran says like that? Why this Quran verse contradict itself between plural (hearts and visions) and singular(hearing)? Christian claims this verse as scientific and Grammer error. Please give me clarification about this varse.
An-Nahl 16:78 English - Sahih International And Allah has extracted you from the wombs of your mothers not knowing a thing, and He made for you hearing and vision and intellect that perhaps you would be grateful.
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
The use of the Arabic word Af’idah (hearts) in plural form in the verses does not entail the meaning that each person has multiple hearts. Rather, the verses address all people in that they have hearts, and this is why the plural form is used.
As for the use of Sam‘ (hearing) in the singular form and Absaar (visions) and Af’idah in the plural form in the Quran, the scholars wrote extensively on this topic, but there is no room for quoting all of their writings here. One of the best statements made in this regard is: “The Sam‘ (hearing) is used in the sense of a verbal noun – i.e. the sense of hearing – and this is why it is used in the singular form, contrary to Absaar and Af’idah, which refer to the respective body organs that are responsible for vision (eyes) and intellect (mind). Moreover, the sense of hearing deals with limited input, namely sounds, and a person does not have a choice in hearing the sounds produced around him, unlike visions and hearts, for they are associated with multiple inputs and the person has a choice in that. He chooses to lower his gaze from what he wills and to stop thinking about what he wills.”
Allah Knows best.