Sound reflection & controversy in ray diagram of concave mirror

[Laven]

I've two questions here:-
1) Sound reflects it is said using laws of reflection of light.So,it means we hear max. sound when angle of incidence is equal to angle of reflection,right?& if not equal then what do we hear or not?
I guess we hear lesser than max.sound when the angles are not equal.

2) Well,I've drawn ray diagram for concave mirror keeping object exactly at center of curvature according to book the image should form at the same point i.e center of curvature.But it won't, I've tried many times & quite seriously but doesn't forms image at the center of curvature.The image forms ahead of the object but closer but not exactly at the point.
What's this am i wrong somewhere.Do help me.

You are appreciated for your reply.
Thanks in advance.

 

[Baluncore]

Sorry for the long delay.

I suspect you traced parallel rays for a hemispherical mirror rather than for a parabolic mirror.
A parabolic mirror brings rays that are parallel to the axis to a single focal point.

If you stand with your head at the centre of a spherical mirror you can hear your own voice, louder, but slightly delayed. You can approximate the middle of a parabolic reflector by using a small part of a sphere near the axis, the focal point is then a half radius from the vertex.

https://en.wikipedia.org/wiki/Curved_mirror#Mirror_shape
https://en.wikipedia.org/wiki/Curved_mirror#Concave_mirrors