Can you help me out with my Qs?

1.Researchers studying the sense of audition report that:

            a. decibels are equally distant, as inches on a ruler are.

b. the critical level for dangerous sound intensity begins at 90 decibels.

c. everyday noises are hazardous

d. a 60 decibel sound is twice as loud as a 30 decibel sound.

2.   Our sense of hearing brings us the sound of a C, an E and a G simultaneously on the piano but we interpret the sound as a Gmajor chord due to the process of:
a. perception
b.   specific nerve energy
c.   sensation
d.   functional encoding

3. The dimension of auditory experience related to the frequency of the sound wave (as measured in hertz) and to some extent, its intensity is called:
   a. complexity   b. pitch   c. timbre   d.loudness