The hearing test results are plotted on a graph with the y-axis representing hearing threshold and the x-axis representing frequency.Neoplastic: acoustic neuroma or meningioma.Congenital malformations of the inner ear structures.Ototoxic Medications: aminoglycosides, platinum chemotherapeutics, methotrexate, furosemide, aspirin, etc.Infectious: meningitis, mumps, measles, syphilis, etc.SNHL is often not as amenable to surgical intervention compared to conductive hearing loss.The most common cause of SNHL in the United States is chronic noise exposure.SNHL is the most common type of permanent hearing loss.Sensorineural hearing loss occurs when there is damage to the structures of the inner ear or nervous pathways between the ear and brain.Whispered voice is about 20 dB and normal spoken voice is 50 to 60 dB. A flipped 256 Hz fork corresponds to a 15 dB hearing loss.Sensorineural hearing loss: air conduction > bone conduction (positive Rinne). Conductive hearing loss: bone conduction > air conduction (negative Rinne). Normal: air conduction > bone conduction (positive Rinne). Rinne: Place the tuning fork in front of the ear and over the mastoid and determine in which position it is heard louder.Unilateral sensorineural hearing loss: lateralize to contralateral ear. Unilateral conductive hearing loss: lateralize to affected ear. Normal: heard equally loud in both ears (also equal in symmetric bilateral hearing loss). Weber: Place the tuning fork in the midline and determine which ear its heard louder.

Conductive loss can be assessed with the Rinne and Weber test.

Bone conduction refers to soudn vibration transmitted to the inner ear through the skull.

Air conduction refers to conduction through the entire outer ear mechanism: including auricle, external ear canal, tympanic membrane and ossicles/middle ear.

Conductive hearing losses are more likely to be correctable with surgical intervention than sensorineural losses.

A conductive hearing loss occurs when sound from the environment is unable to be ‘conducted’ to the structures of the inner ear.

A combination of conductive and sensorineural hearing loss is referred to as a “mixed hearing loss.”.

Conductive and sensorineural hearing losses can occur alone or in combination.

Hearing loss can be divided into two types:.

Unable to hear 'loud' stimuli such as lawn mowers or passing cars May lip-read or use hearing aids to assist with communicationĬan understand speech only if the speaker is in close proximity Has difficulty hearing a normal conversation. Has difficulty hearing some quieter conversations. Can hear conversations in a quiet setting but my have difficulty in noisy environments

Conventional pure-tone audiometry (5yo+): raising hand in response to sound stimulus.

Conditioned play audiometry (CPA)(2yo to 5yo): child interacts with toy or object in response to sound stimulus.

Visual reinforcement audiometry (VRA) (6mo to 2yo): child turns to visual cue in response to sound stimulus.

Behavioral observation audiometry (BOA)(0 to 5 mo): observes child response to sound stimulus.

Auditory brainstem response (ABR): use electrodes to monitor brain activity response to sound stimulus, can be done at any age but will often need to be sedated after 6mo.Evoked otoacoustic emissions (EOAE): test function of outer hair cells, often used as a newborn hearing screen.In children testing varies according to age:.The patient’s ability to hear these tones is plotted on a graph to create an audiogram.During testing, the audiometer delivers various “pure tone” sounds at particular frequencies and intensities, from low to high.Human speech usually falls between 250Hz and 6000Hz.Audiograms typically test frequencies between 250Hz and 8000Hz.The average human can hear between 20 and 20,000 Hz.Frequency is measured in Hertz (Hz), which is often thought of as the “pitch” of the sound.For reference, normal conversation is around 60 dB.Standard audiograms test between 0 and 110dB.An increase of 20 dB means the sound is 100-fold more intense.An increase of 10 dB means a 10-fold increase in sound intensity.The decibel scale is logarithmic (based on a factor of 10):.Intensity of sound is measured in decibels (dB) which can be thought of as the ‘loudness' of the sound.The results of an audiogram can help direct medical and surgical interventions to improve and/or preserve hearing function.

Hearing loss can be divided into two categories: conductive or sensorineural.Audiograms are created by plotting the thresholds at which a patient can hear various frequencies.Audiograms are used to diagnose and monitor hearing loss.

Rinne test conductive hearing loss