Articulation index
Encyclopedia
The Articulation Index is a tool used by audiologists to predict the amount of speech that is audible to a patient
with a specific hearing loss
. The AI reading for a given patient can range from zero to 1.0, representing the proportion
of the average speech signal that is audible. The closer the AI is to 1.0, or 100 percent
, the better the person should be able to hear speech.
The AI is often used as a counseling tool since it presents an individual’s hearing loss in terms of percentage of speech missed during a typical one-on-one conversation. The AI can also be used to measure the effectiveness of hearing aid
s and other forms of amplification devices.
Since the creation of the AI, there have been several proposed ways to simplify and increase its use in the field of audiology
. In 1990, Gustav Mueller and Mead Killion proposed an AI calculation
involving one hundred dots on an audiogram
, each of which represented an important speech frequency
; the number of dots audible to the listener, multiplied by .01, represented the patient's AI. Unfortunately, not all areas on the audiogram (taking into account frequencies and intensity levels) are equally weighted. According to this procedure, the highest density of the audiogram dots is concentrated in the frequency region of 1-3 kHz
, which means that this is the region containing the most speech information.
Patient
A patient is any recipient of healthcare services. The patient is most often ill or injured and in need of treatment by a physician, advanced practice registered nurse, veterinarian, or other health care provider....
with a specific hearing loss
Hearing impairment
-Definition:Deafness is the inability for the ear to interpret certain or all frequencies of sound.-Environmental Situations:Deafness can be caused by environmental situations such as noise, trauma, or other ear defections...
. The AI reading for a given patient can range from zero to 1.0, representing the proportion
Proportionality (mathematics)
In mathematics, two variable quantities are proportional if one of them is always the product of the other and a constant quantity, called the coefficient of proportionality or proportionality constant. In other words, are proportional if the ratio \tfrac yx is constant. We also say that one...
of the average speech signal that is audible. The closer the AI is to 1.0, or 100 percent
Percentage
In mathematics, a percentage is a way of expressing a number as a fraction of 100 . It is often denoted using the percent sign, “%”, or the abbreviation “pct”. For example, 45% is equal to 45/100, or 0.45.Percentages are used to express how large/small one quantity is, relative to another quantity...
, the better the person should be able to hear speech.
The AI is often used as a counseling tool since it presents an individual’s hearing loss in terms of percentage of speech missed during a typical one-on-one conversation. The AI can also be used to measure the effectiveness of hearing aid
Hearing aid
A hearing aid is an electroacoustic device which typically fits in or behind the wearer's ear, and is designed to amplify and modulate sound for the wearer. Earlier devices, known as "ear trumpets" or "ear horns", were passive funnel-like amplification cones designed to gather sound energy and...
s and other forms of amplification devices.
Since the creation of the AI, there have been several proposed ways to simplify and increase its use in the field of audiology
Audiology
Audiology is the branch of science that studies hearing, balance, and related disorders. Its practitioners, who treat those with hearing loss and proactively prevent related damage are audiologists. Employing various testing strategies Audiology (from Latin , "to hear"; and from Greek , -logia) is...
. In 1990, Gustav Mueller and Mead Killion proposed an AI calculation
Calculation
A calculation is a deliberate process for transforming one or more inputs into one or more results, with variable change.The term is used in a variety of senses, from the very definite arithmetical calculation of using an algorithm to the vague heuristics of calculating a strategy in a competition...
involving one hundred dots on an audiogram
Audiogram
An audiogram is a standard way of representing a person's hearing loss . Most audiograms cover the limited range 100 Hz to 8000 Hz which is most important for clear understanding of speech, and they plot the threshold of hearing relative to a standardised curve that represents 'normal'...
, each of which represented an important speech frequency
Audio frequency
An audio frequency or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human...
; the number of dots audible to the listener, multiplied by .01, represented the patient's AI. Unfortunately, not all areas on the audiogram (taking into account frequencies and intensity levels) are equally weighted. According to this procedure, the highest density of the audiogram dots is concentrated in the frequency region of 1-3 kHz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
, which means that this is the region containing the most speech information.