A Mode of Recording the Results of a Hearing Test - Report Example

An audiogram is a mode of recording the results of a hearing test. The test is done wearing a pair of headphones. Tonal sounds will be put into one or other ear by the audiologist using an audiometer. The person indicates when he hears the sound by pressing a button or raising his hand. The audiologist will then measure the very lowest sound that can be heard and record that level both at different volumes and at different pitches. The hearing test is called "pure tone audiometry". It is a standard way of representing a persons hearing loss. An audiogram includes a table and a graph showing how various frequencies of sound are heard in each ear. This graph is the main feature of audiogram and measures the lowest volume of pure tone signals that can be heard at different frequencies for each ear. It also record results of other tests that indicate how various parts of "hearing system" are working. It may include ability to recognize words and words in context, ability to hear in noisy situations, the flexibility and response of eardrum and auditory brainstem response. Most audiograms cover the limited range of 100Hz to 8000Hz which is important for clear understanding of speech, and they design the threshold of hearing relative to a standardized curve that represents normal hearing, in dBHL. Low sounds vibrate more slowly than high sounds. The frequency at which sounds vibrate is measured in hertz. The audiogram only tests pure pitch. The pitches tested on an audiogram may range from 125 hertz to 8000 hertz. There are some different styles of audiograms, but commonly a standard set of symbols is used for representing items on the chart. The audiogram reads in frequency (pitch) across horizontal axis and it reads in decibels (loudness) down the vertical axis. The pitches are low on the left side (125 or 250Hz), and then gradually ascend to higher pitches on the right side (8000Hz). The loudness scale goes from very soft sounds at the top (-10 or 0dB) to very loud sounds at the bottom (110 dB). Normal conversational speech is about 45 dB. The softest sound a person hears at each pitch is considered their hearing threshold. Thresholds are marked for most of the pitches across the audiogram. In testing with headphones, they are called "air" thresholds as the sound must travel through the air of the ear canal to be heard. An O is used for the right ear and an X is used for the left ear to represent the air thresholds. A bone-conduction vibrator is a device that gently rests on the mastoid process of the skull. When a bone-conduction vibrator is used to test for thresholds, a < symbol is used for the right ear and a > symbol is used for the left ear. By comparing the headphone thresholds with the bone vibrator thresholds at each pitch, it can be determined if a hearing loss is conductive, sensorineural or mixed. If the air conduction thresholds show a hearing loss but the bone conduction thresholds are normal, then we call it a conductive hearing loss. If both the air conduction thresholds and the bone conduction thresholds show the same amount of hearing loss, it is called a sensorineural hearing loss. A mixed hearing loss is when the bone conducted thresholds show a hearing loss and the air conducted thresholds show an even greater hearing loss.  The typical ranges for an adult hearing are: -10 dB to 25 dB = Normal range 26 dB to 40 dB = Mild hearing loss 41 dB to 55 dB = Moderate hearing loss 56 dB to 70 dB = Moderately Severe hearing loss 71 dB to 90 dB = Severe hearing loss Over 90 dB = Profound hearing loss. The sounds used to produce speech in conversation have frequencies and decibels. The most distinctive frequency and decibel for each speech sound is graphed on an audiogram to provide information about what sounds can be heard at specific degrees of hearing loss. When the entire sounds essential for speech were initially graphed and a line was drawn around them, the shape looked like a banana. The term "speech banana" was introduced so. This area is the target hearing area for children with hearing loss. People with good hearing will have results that are located above the speech banana which means that they can hear sounds at both lower and higher frequencies than normal human speech, and lower decibel levels than normal human speech. If hearing test results fall below or within the speech banana, it means that the person may have difficulty in hearing people talk. Children with different levels of hearing loss will produce different audiograms. For instance Jet planes have a loud, high decibel, high frequency sound while wind rustling is a lower decibel sound. A child may be able to hear certain low frequency sounds such as [m] but not hear higher frequency sounds such as [s] and [sh]. Missing such sounds result in a change in understanding what is said. To compare and contrast the audiograms of two children with two levels of hearing loss will be useful. The following are examples of audiogram of child A, who has a mild to moderate hearing loss in both ears and of child B who has a moderate to severe hearing loss. 41 to 55 db (mild loss) 71 to 90 db (severe loss) Child A understands conversational speech at a distance of 3 to 5 feet (face to face) and may miss about 50% of class discussions. He may have limited vocabulary and may have speech irregularities. Child A should be referred for special education evaluation. He may benefit from individual hearing aid and training. He needs favorable seating and probable special education supports. More attention needs in vocabulary and reading. He may need speech reading instruction, speech conversation and correction, if indicated. Child B may hear loud voices about 1 foot from the ear. He may be able to identify environmental sounds and vowels but not all consonants. His speech and language are likely to be impaired or to weaken and they may not develop spontaneously if loss is present before 1 year of age. He needs a special education program with emphasis on all language skills, concept development, speech reading, and speech. Needs specialized program supervision and comprehensive supporting services. He can benefit from individual hearing evaluation and auditory training on individual hearing evaluation. Works Cited www.batod.org.uk The British Association of teachers of the deaf, 2010. Web. 14 Oct 2010. www.stammering.org The British stammering Association, 2010. Web. 15 Oct 2010 www.ahearingloss.com Say What Club, 2010. Web. 15 Oct 2010. www.hearingtherapyaustralia.com Hearing therapy Australia, 2007. Web. 15 Oct 2010 www.audiologyawareness.com Audiologists caring for America’s hearing, 2010. Web. 14 Oct 2010 www.theitinerantconnection.com The Itinerant connection, 2010. Web. 14 Oct 2010 Read More