The bony, spiral-shaped, fluid-filled sense organ used for hearing is the

Generally the ear, and more specifically the cochlea

The ear is composed of 3 parts namely:
 1. The outer ("external") ear, composed of the pinna and ear canal, 
 2. The middle ear, composed of tympanic cavity and three ossicles, 
 3. The inner ear, composed of semicircular canals, the utricle, saccule, and the cochlea. 

Hearing happens initially by allowing the pinna of your ear to focus the sound. Then, by means of the ear canal and the ossicles, the sound is sent to the fluid-filled eardrum, which begins to vibrate. The vibrations are sent to the snail-shell looking component of the inner ear called the cochlea. The cochlea senses these vibrations and converts them to nerve impulses to be interpreted by the brain, making you "hear" the sound. 

answer: carbon 14 can only be used to determine the age of the organisms that were once living, and igneous rocks are non living.

explanation:

carbon 14 dating is used to determine the age of the sample by estimating the amount of carbon 14 present in the sample and then comparing it with a reference standard.carbon 14 is a isotope of carbon which is radioactive and unstable. carbon 14 is assimilated by all plants and animals throughout their life from carbon dioxide. however, one the organisms die they stop this assimilation and the carbon 14 content starts to decrease.by knowing how much of carbon 14 is left in an organism after his death, one can estimate the age of the organism. the materials whose age can be estimated by carbon 14 method are the organic compounds. however, some inorganic compounds such as aragonite   shell can also be dated.however, if we consider the igneous rocks it is a non living component which never accumulated carbon 14 in it and thus, we cannot use carbon 14 dating method to estimate its age.