The following study published in the Journal of the American Academy of Audiology identifies a link between cigarette smoking and permanent hearing loss. The health of the inner ear organ of hearing, the cochlea, depends on an adequate supply of oxygenated blood. Smoking, long known to cause vascular insufficiency, appears to minimize the flow of blood to the cochlea. In addition, hypoxia can occur when carbon monoxide in the blood of smokers prevents the cochlea from getting enough oxygen.

Negley C., Katbamna B., Crumpton T., Lawson G., (2007). Effects of cigarette smoking on distortion product Otoacoustic emissions. J Am Acad Audiol 18: 665-674.