For awhile, my iphone 6S had an issue where I couldn't hear calls at all unless they were on speaker. Then I dropped it and the screen shattered into a million pieces and I had the screen replaced. Now I can hear my calls without the speaker.
When I had the problem, I'd try to be as discreet as possible - I rarely make calls anyway and I'd try to be quiet and not speak about anything weird or controversial. But occasionally I did have to take a call and the only way to do it was on speaker. it sucked. Glad that's over.