Tests For Hearing
High frequency audiometry is used in: [AIIMS May 12]
|C||Non-organic hearing loss|
Conventional audiometry tests frequencies between 0.25 kHz - 8 kHz, whereas high frequency audiometry tests in the region of 8 kHz-20 kHz. Some environmental factors, such as ototoxic medication like aminoglycosides and noise exposure, appear to be more detrimental to high frequency sensitivity than to that of mid or low requencies. Therefore, high frequency audiometry is an effective method of monitoring losses that are suspected to have been caused by these factors. It is also effective in detecting the auditory sensitivity changes that occur with aging
Ototoxic drugs like aminoglycosides typically affecting higher-frequency hearing first and progressing to lower frequencies.
• Otoacoustic emissions (OAE) are more sensitive at detecting auditory dysfunction than high-frequency pure fone audiometry.
OAEs also have the added advantage of being practical at bedside and do not require a soundproof room.
• Distortion product OAEs are more sensitive than transient evoked OAEs for the detection of early signs of ototoxicity.