Chemical energy is transduced to the electrochemical energy of neural impulses at the

retina
cochlea (i know this one isn't right)
ganglion cells
olfactory mucosa
semi-circular canals

olfactory mucosa because the nose (olfactory - sense of smell) uses chemo - like receptors (usually hair) that can perceive the smell in form of chemicals and send those signals to the brain to interpret the smell. Whatever you smell, you are essentially the chemicals that made up that substance! Even food or anything!