Anotoacousticemission (OAE)is described as a low-level sound emitted by the Cochleaspontaneously. It can also be evoked by an auditory stimulus. Theparticular information provided by OAEis associated with the function of the outer hair cells. The use ofotoacoustic emission in routine audiological has significantlyincreased over the past 20 years (Knight, 2007). The OAEsare routinely employed in the pediatric population to verify andascertain behavioral responses so as to obtain additionalfrequency-specific information. They are also routinely used innewborn hearing screening programs across the entire world.
Hearing is measured at varying frequencies ranging from low pitches(250 Hz) to high tones (800 Hz). The levels of hearing are quantifiedabout normal hearing in decibels. The greater the number of DB theworse the hearing condition becomes (Bagai A, 2006).
Wheneverthere is a hearing loss, it is important to investigate whether theproblem has been caused by sensory problem also referred to assensorial hearing loss or mechanical problem called conductivehearing loss (Bagai A, 2006). The difference between the two is madeusing a bone vibrator. The bone vibrator passes the mechanical partsof the ear. If the hearing is far much better while using the bonethan the air, it means there is a conductive hearing loss.
Thereexists other special subsets of audiometry procedure. The speechaudiometry comprises of reading a list of words to test if patientsare in a position to discriminate words. The Acoustic reflex testinginvolves subjecting the ear to some loud sound and observing whetheror not it causes a stapedius muscle to tighten the stapes (Bagai A,2006).
Otoacoustic emissions assess hearing in new babies and determines thefunctioning of the cochlea. This method can be used to evaluatehearing responses to treatment and helps to choose the appropriatetherapy (Bagai A, 2006)
Bagai A, T. P. (2006). Does this patient have hearing impairment? JAMA , 295(4):416-28, .
knight, K. R. (2007). Journal of clinical Oncology. Early changes in auditory function as a result of platinum chemotherapy: use of extended high-frequency audiometry and evoked distortion product otoacoustic emissions. , 25(10).