What is db hl

Tele-Audiology and the Optimization of Hearing Search inside this book for more research materials. Recommend to a Librarian Recommend to a Colleague. Looking for research materials? Search our database for more dB HL downloadable research papers. Full text search our database of , titles for dB HL to find related research papers. Handbook of Research on Evidence-Based Persp While yoga was originally intended to be practiced In Stock.

Handbook of Research on Clinical Application Because our outer and middle ear transmits frequencies near 4 kHz very efficiently, hair cells that are tuned to frequencies near 4 kHz are particularly vulnerable to noise damage.

Therefore, audiograms of patients with noise damage often have characteristic 4 kHz notches, as shown here:. Even if we avoid exposure to very loud noise, the ear's outer hair cells may also simply wear out as we age, leading to age related hearing loss. In this condition, high frequency outer hair cells tend to die off before low-frequency ones, possibly because the high frequency outer hair cells have to work harder if their job is to amplify acoustic vibrations on a cycle by cycle basis.

Consequently, patients with age-related hearing loss often have normal sensitivity at low frequencies, but progressively poorer sensitivity for higher frequencies, as shown here:. If you are curious about what the effect of such age related hearing loss would be, try our Age Related Hearing Loss Simulator. Conductive Hearing Loss Conductive hearing loss comes about when the transmission of sound to the inner ear is impaired, perhaps due to impacted ear wax cerum , an ear infection otitis media with effusion or OME , or calcification of the middle ear ossicles otosclerosis.

Sensory-Neural Hearing Loss By far the most common cause of sensory neural hearing loss is damage to sensory hair cells in the cochlea. Hosford-Dunn Eds. Audiology: Diagnosis. Detection is simply the ability to determine if a sound is present or absent, whereas discrimination is the ability to determine the difference between two stimuli or sounds. For example, during speech audiometry patients are asked to repeat spondee words e. Sometimes, an SRT cannot be measured and the audiologist is simply interested in measuring the level dB HL where the patient is aware that speech is present speech awareness threshold , or SAT.

Another common measure used by audiologists is the word recognition score WRS. The WRS is a speech discrimination measure in which the patient repeats a list of 50 common, one syllable monosyllabic words.

The minimum audible angle MAA is the smallest change in the location azimuth of two sound sources that can be perceived by a listener.

Figure 1. From: Gelfand, S. Hearing: An introduction to psychological and physiological acoustics. New York: Marcel Dekker.