Talk:Audiogram

Suggestions by Wesley R. Elsberry
First, "dbSPL" is wrong (more on that below, including authoritative reference excluding that term). Second, audiograms are also used in reference to species, including non-human species, so "for a person" is wrong in two ways. The correct way to report decibels is with the "dB re" formalism, with the reference effective pressure noted in the measurement.

Other sites using the "dB re" formalism: Oceans of Noise (explicit in defining SPL and SIL in terms of "dB re"), SURTASS LFA, NIST listing SPL in terms of "dB re", and Acoustic Impacts on Marine Mammals. But the best thing I've found has to be ASACOS Rules for Preparation of American National Standards in ACOUSTICS, MECHANICAL VIBRATION AND SHOCK, BIOACOUSTICS, and NOISE, which states:

3.16 Unit symbols 3.16.1 When to use unit symbols

In the text of the standard, the unit symbol for a quantity shall be used only when the unit is preceded by a numeral. When the unit is not preceded by a numeral, spell out the name of the unit. In text, even when a numerical value is given, it is desirable to spell out the name of the unit. Moreover, the name shall be spelled out when it first appears in the text, and more often if the text is lengthy.

Thus, in text write "...a sound pressure level of 73 dB; or "...a sound pressure level of 73 decibels." Do not write "sound pressure level in dB"; the correct form is "sound pressure level in decibels." Do not write "dB levels", "dB readings", or "dB SPL."

Levels or readings are not of decibels; they are of sound pressure levels or some other acoustical quantity. Write out the word "decibel" for such applications, and be sure that the word 'decibel' follows, not precedes the description of the relevant acoustical quantity. The guidelines given for the National Standards clearly excludes the use of "dB SPL". Wesley R. Elsberry 17:13, 9 April 2006 (UTC)


 * Heading added ~ ToBeFree (talk) 21:36, 2 June 2019 (UTC)

Article revision
I can contribute the following text, which is modified and expanded from my page on testing the hearing of whales and dolphins. I'd like to get a little feedback before simply replacing the current text. I think the current text is problematic in several ways.

An audiogram is a graphical representation of how sensitive a subject is to acoustic stimuli across a range of frequencies. Frequency is placed on the X axis, usually with a logarithmic scale, and threshold values, usually in decibels, are plotted on the Y axis. For a behavioral audiogram, researchers obtain the needed threshold values by training subjects to respond to test tones with a specific behavior, which allows the tester to determine which tones have been heard and which were not heard (but see detection theory). For most humans, this may be accomplished by asking them to press a button or speak a word when they hear a test tone. From repeated trials, researchers estimate the threshold of hearing at each test frequency. Researchers do the same for a number of frequencies of test tones to find the audiogram of the subject.

For a behavioral audiogram, the subject is trained to make a response to an acoustic stimulus. The acoustic stimuli are given at many different frequencies and amplitudes, and an estimate is made of the threshold of hearing for each frequency. This approach contrasts with audiograms taken using electronics to pick up the faint signals of the brain's response to those stimuli, or neurophysiological audiograms. A common approach to obtain a neurophysiological audiogram is to monitor the auditory brainstem response (ABR). While a neurophysiological audiogram by ABR has the advantage of not being dependent on having trained subjects, it has the disadvantage of requiring even more sophisticated equipment and impeccable technique in order to carry it off. Also, neurophysiological and behavioral audiograms do not usually agree precisely, even when taken on the same subject. A neurophysiological audiogram tends to indicate several decibels better sensitivity across the tested frequencies than does a behavioral audiogram.

A neurophysiological method for human subjects that is not as precise as ABR, but which can be accomplished with less complex equipment, relies upon otoacoustic emission. The healthy human ear not only transduces received sound energy, but also produces evoked otoacoustic emission of sound in response to acoustic stimuli. A small microphone placed in the external ear canal can pick up these small signals and indicate that the ear can react to a particular stimulus, or indicate a hearing deficit if no response occurs to a normally audible test tone. Such a technique is useful for constructing an audiogram of a human subject who cannot complete a behavioral audiogram, as in severe cases of autism.

As anthropogenic noise becomes more widespread, concerns about impacts of noise on animal populations grows. Audiograms for species become important tools for researchers and policy makers to take into account when dealing with anthropogenic noise. Unfortunately, relatively few species of birds or marine mammals have had audiograms constructed for them. For example, there is no audiogram of any type available for any mysticete cetacean.

A problem with audiograms of non-human subjects is that there is often a tendency to use an audiogram obtained from a single subject and treat that as a representative audiogram for an entire species. This famously led to many years of confusion, from 1972 to 1999, as researchers believed that killer whales could not hear frequencies above about 32 kilohertz, based upon an audiogram of one subject. Later, audiograms taken on other killer whales revealed that their hearing was similar to that of other odontocete cetaceans, with ultrasound sensitivity up to about 120 kilohertz, indicating that the original subject had extensive high-frequency hearing loss.Szymanski et al. 1999

Another issue concerns the completeness of testing for an audiogram. For decades, shad were considered to have an ordinary audiogram for fish, with peak sensitivity under 1 kHz and an upper limit of hearing between 1 and 2 kHz. Further testing, however, demonstrated that shad actually could detect ultrasonic sound up to about 180 kHz. Wesley R. Elsberry 08:07, 12 April 2006 (UTC)

Ambiguity of meaning
According to this article an audiogram represents ability to hear over the frequency range, but it also represents a normalised version relative to 'normal' hearing in dBH. It can't be both can it? Absolute response curves are called equal-loudness contours. Are the two synonymous? If an audiogram is by definition relative to the norm, and hence primarily a measure of hearing loss, then there can surely be no such thing for and animal (how would you test it and what would be the point). Much of this article seems to be about animals' 'hearing range', and not audograms as such. --Lindosland (talk) 13:58, 5 March 2008 (UTC)

The graphs shown are not actually audiograms. The top one shows bands of hearing loss, but no actual audiogram (I hope to prepare better ones). I've corrected the title on one for now. I've created a page hearing range which was previously a redirect to here, and I think all material on animals should go there, making room here for a lot of detailed material on actual human audiograms (an animal audigram is not an impossibility I guess, but as far as I know a very rare thing given that animals can't tell you where their hearing threshold is!). --86.135.179.99 (talk) 14:35, 5 March 2008 (UTC)

In line with the above comments I've moved the content on animal hearing to Hearing range, and created a redirect at Animal hearing. I've started to add content here that is relevant to the major use of audiograms, which is to diagnose hearing loss in humans. I note that such details are not given at Audiometry or Sensorineural hearing loss so would like to present a collection of typical audiograms here when I have created some that are copyright free. This page can then take a lot more content on how audiograms are measured and defined, including a definition of 'normal' as used for the reference levels. --Lindosland (talk) 15:43, 5 March 2008 (UTC)

Information needed
In the measurement section, the ANSI standards listed need to have citations.

It would be beneficial if more detail was given on the symbols used on the audiogram (X is for the left ear and O is for the right ear, bone conduction symbols which show whether there is a conductive hearing loss present). This would allow for the section on diagnosing hearing loss to have more information.

Threshold should be defined and cited.

In the first section, the normal hearing criteria for humans is listed. Later on in the first section children are discussed. Because children are brought into the page, it should be noted that children have a different criteria for hearing loss, which needs to be mentioned.

Discussing otoacoustic emissions and ABR's is distracting from the topic. When discussing the audiogram, only objective measures should be discussed given that the previously listed objective tests are not recorded on the audiogram. AshleyStumpf (talk) 03:19, 4 September 2016 (UTC)

External links modified
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Add new section
Hi! I'm new to Wikipedia. I have prepared a new information for the article audiogram. Please check if this information can be added to the article or if additional changes are needed. Thank you!

There are mobile applications that are equipped with a function for audiometric hearing test and hearing aid applications, with a hearing test function.

The result of hearing test using a mobile application are user's hearing thresholds (audiogram) at different frequencies (125 Hz ... 8 kHz). User's hearing thresholds using mobile application are determined with a small error. Despite the error, the hearing test can determine the degree of hearing loss. .

Hearing test results are presented to the user in an easy-to-understand way: in a graphical form and as a text. On the diagram the sounds are often visualized in the audible and inaudible frequency domain. Additionally, the user is provided with the data on the detected hearing loss degree (which sounds they will hear or not) and hearing age norms.

Maxim.porhun (talk) 17:23, 2 June 2019 (UTC)


 * Hi, let's wait if someone has an objection within the next, say, one or two weeks. If nobody has, feel free to make this edit yourself (be bold!) Face-smile.svg ~ ToBeFree (talk) 21:31, 2 June 2019 (UTC)
 * I have some doubts about the text. Unless "in-situ audiometry" is code for "mobile apps", reference 2 doesn't seem to be about the topic of the rest of the proposed addition. It also reports errors of 10-15 dB, which seem rather large to me and apparently are large enough to lead to the fitting of a different hearing aid. "presented to the user in an easy-to-understand way" makes the text read like an advertisement and is irrelevant to the topic of the article. I don't speak Russian or Spanish, but I don't see that the Spanish source supports the statements it's cited for, and it doesn't seem to mention audiograms at all. I wonder whether there's a conflict of interest to declare. Huon (talk) 22:28, 2 June 2019 (UTC)