Why you never hear doctors say "oh" to acknowledge a patient's answer

𝐖𝐡𝐲 𝐲𝐨𝐮 𝐧𝐞𝐯𝐞𝐫 𝐡𝐞𝐚𝐫 𝐝𝐨𝐜𝐭𝐨𝐫𝐬 𝐬𝐚𝐲 "𝐨𝐡" 𝐭𝐨 𝐚𝐜𝐤𝐧𝐨𝐰𝐥𝐞𝐝𝐠𝐞 𝐚 𝐩𝐚𝐭𝐢𝐞𝐧𝐭'𝐬 𝐚𝐧𝐬𝐰𝐞𝐫?
Take this everyday exchange:
𝑊ℎ𝑒𝑛 𝑑𝑖𝑑 𝑦𝑜𝑢 𝑔𝑒𝑡 𝑏𝑎𝑐𝑘?
𝑌𝑒𝑠𝑡𝑒𝑟𝑑𝑎𝑦.
𝑂ℎ.

You've been that first person countless times, dropping a casual "oh" to acknowledge an answer without thinking twice about it. But you will never hear a doctor respond with "oh" when a patient answers their questions.

Why not?

That little "oh" is actually doing serious work. It signals "I didn't expect that answer" or "That's new information to me."

Doctors don't want to signal to the patient that their answer is unexpected and surprising, both because doctors want to appear knowledgeable and because no patient wants to hear that their symptoms are interesting and unique.