How To Read Audiogram ResultsAn audiogram is used to plot the softest sounds you are able to hear and forms a graphical representation of a your hearing health. The amount of information recorded on an audiogram will vary based on how many tests your examiner chooses to perform.  This section is designed to give you a basic understanding in reading an audiogram and understanding audiogram results.

Reading an Audiogram?

The air-conduction exam (the test when you are wearing headphones and listening to beeps) is presented at 250Hz, 500 Hz, 1000Hz, 1500Hz, 2000Hz, 3000Hz, 4000Hz, 6000Hz and 8000Hz.  These numbers (measured in Hz) represent the frequencies (pitches) of the sounds presented during air-conduction testing. They can be thought of as keys on a piano ranging from the bass notes (250 Hz) to the treble notes (8000 Hz).

On the left and right side of the graph below there are numbers from -10 to 110. These numbers (measured in dB) represent the intensity (loudness) of the sound presented.

What the symbols on the graph mean:

The symbols represent the quietest level you responded at each frequency (pitch) during the hearing test.

The 'X's' are the responses for the left earThe '0's' are the responses for the right ear

 The audiogram results above illustrates a high frequency hearing loss.  We would categorize this hearing loss as: Normal hearing in the low tones, sloping to a severe hearing loss in the middle and high frequencies.  The above high frequency hearing loss is best fit with an Open-fit hearing aid, meaning our SmartAid Digital and SmartAid Digital Premium are the best choices.

Categories of Hearing

Normal Hearing  is defined as hearing thresholds in the range -10 to 25 dB

Mild Hearing Loss  is defined as hearing thresholds in the range 25 to 40 dB

Moderate Hearing Loss  is defined as hearing thresholds in the range 40-55 dB

Moderately-Severe Hearing Loss

 is defined as hearing thresholds in the range 55-70 dB

Severe Hearing Loss  is defined as hearing thresholds in the range 70-90 dB

Profound Hearing Loss  is defined as hearing thresholds in the range 90 dB+

 

Your audiogram may show additional information that isn't plotted on the audiogram above.  This information can explain more detail about how your ear works, but isn't utilized when we program your hearing aids. This information may include:

Bone Conduction   Tests response of inner ear, helps determine if hearing loss is sensorineural or conductive in nature.

Speech Reception (SRT)

A test to determine the lowest level of speech you can understand.

Most Comfortable Level (MCL)

A test to determine the decibel level that you find speech to be the most comfortable to listen to in a quiet environment.

Uncomfortable level (UCL)

A test to determine the decibel level that you find speech to be uncomfortably loud.

 

IMPORTANT: A hearing test should be performed by a qualified Hearing Aid Dispenser, Audiologist or Ear Doctor.

If you would like us to provide an interpretation of your audiogram results, including a recommendation of the best hearing aid design and technology to choose to aid your hearing loss, you can submit a copy of your audiogram to our team of hearing professionals.  

What do different audiograms look like?Webpage published: 2011/Last reviewed: 2012

 

Different kinds of hearing loss have differently shaped audiograms. By comparing the air conduction thresholds (O or X) with the bone conduction thresholds ([, Δ, ] or Δ) at each pitch, we can determine if a hearing loss is conductive or sensorineural.

Some examples are given below:

What does an audiogram showing conductive deafness look like?

If the bone conduction levels differ from the air conduction levels, sound waves are probably being obstructed on their passage through the eardrum and middle ear. This audiogram shows a right sided conductive hearing loss, possibly caused by perforation of the eardrum or 'glue ear' (congestion behind the eardrum which is common in children).

 

What does an audiogram showing sensorineural hearing loss look like?

If air and bone conduction are the same, it indicates that the problem is likely to be located in the inner ear. We call this a sensorineural hearing loss. The audiograms below show (a) bilateral mild sensorineural hearing loss and (b) bilateral moderate sensorineural hearing loss.

(a) Bilateral mild sensorineural hearing loss  

(b) Bilateral moderate sensorineural hearing loss

Age related hearing loss (presbyacusis)

The audiograms below show bilateral (both ears) age related hearing loss. With age related hearing loss a person can usually hear low-pitched sounds better than high-pitched sounds. Clarity of sound is affected - 'I can tell that someone is talking but cannot understand what they have said'.

(a) Right sided age related hearing loss (presbyacusis)

       

(b) Left sided age related hearing loss (presbyacusis)

Hearing loss caused by Menieres Disease      

Typically, the audiogram of someone with Menieres Disease slopes from right to left. Thus, the person with this audiogram will be able to hear high-pitched sounds better than low-pitched sounds in the left ear. The right ear hears perfectly.

So, if you have a moderate sensorineural unilateral hearing loss caused by infectious parotitis don’t panic. It is just the medical way of saying you have nerve deafness in one ear caused by mumps and have problems hearing sounds which are quieter than 41dB. 

Please do not be afraid to ask the ENT doctor or audiologist to explain your hearing chart to you

This shows the results of testing a right ear.

All hearing thresholds are within normal limits.

Note that the air conduction thresholds are connected with a solid line.  Bone conduction thresholds are not connected.

At 250 and 1000 Hz, there is a 5 dB air-bone gap, but that is not significant.  The bone-air gap at 4000 Hz is also not meaningful. Large or consistent bone-air gaps probably mean the bone oscillator is not positioned correctly.

This right ear has a mild loss.  Note that all the thresholds by air conduction are in the range of 30 to 40 dB HL.  Hearing thresholds in the range of 26-40 indicate a mild hearing loss.

The loss is conductive.  We know this because the bone conduction thresholds are within the normal range.

When the audiologist describes this audiogram, he or she would say “The right ear has a mild, flat conductive loss.”  The audiologist would not separately describe the severity of the bone conduction scores in the report, even though this is part of the thought process you go through when deciding on the type of loss.  “Flat” refers to the audiometric configuration.  The thresholds are relatively equal across frequencies.  

This left ear has a sensorineural loss.  In the low frequencies (1000 Hz and below), the loss is mild.  In the high frequencies the loss is moderate to moderately severe. Note that at 2000 Hz the threshold is 55 dB HL, which is in the moderate category.  The 60 dB HL threshold is moderately severe.  When thresholds cross a category boundary, list both when describing the severity of the loss. The loss is sensorineural because there are no significant air-bone gaps.  There is essentially equal loss by air and by bone conduction.

The audiologist would describe this as a mild, gradually sloping to moderately severe sensorineural loss.  Gradually sloping means that most of the thresholds go down by 5 to 15 dB each octave.

This left ear has a mixed loss.  The loss ranges from moderate in the low frequencies, to severe in the high frequencies and is gradually sloping.

In examining the audiogram, ask yourself q Is there a loss? q Is the bone conduction normal? q Are there any air-bone gaps? Because bone conduction is not normal, we know that at least part of the loss is sensorineural.  Because there are significant (larger than 10 dB) air-bone gaps, there is a conductive component.  Because both a conductive and sensorineural component exist in the same ear, the loss is mixed.

The audiologist might say “The moderate, sloping to severe mixed loss has air-bone gaps of 20-30 dB across the frequency range.”

The right ear has a mixed loss.  The loss is moderate in the low frequencies, improving to mild in the mid frequencies, and decreasing to moderately severe to severe in the high frequencies.

In answering the questions: q Is there a loss? q Is the bone conduction normal? q Are there any air-bone gaps? You will note that the air-bone gaps are not at each frequency, but only in the low frequencies.  In the mid to high frequencies, the loss is sensorineural.  When one ear has both a conductive component and a sensorineural component, the loss is mixed.  The conductive and sensorineural components do not have to be at the same frequency, just the same ear.

The audiologist might say “This mixed loss is mild to moderately severe, with best hearing in the mid frequencies.  The conductive component is restricted to the low frequencies.”

Conductive Loss 

Sensori- neural Loss 

Mixed Loss

Air conduction thresholds(normal or loss?) 

LOSS LOSS LOSS

Bone conduction

NORMAL

LOSS LOSS

thresholds (normal or loss?) 

Air-bone gap (significant or not significant) 

Significant

None or not significant

Significant

Location of problem

Outer or middle ear

Inner ear or retro-cochlear

Partially outer/middle; part inner/retro

Is there ever a case when you might not be testing the ear you think you are testing?      

Could you ever present the sound to the right ear and have the left ear hear it?  

 

What is masking?      

Why is it used?

Masking is sound presented to the non-test ear to keep it “busy”, keep it from hearing the sound presented to the test ear. The sound is a noise, which sounds like static, but has tonality.  By properly presenting masking noise to the non-test ear, you can be sure that you are testing the ear to which the pure tone is presented.

Masking can be done when testing either air or bone conduction.  

What are the symbols that are used to note that masking noise was presented in the non-test ear?

Once you have memorized the X and O for left and right, it may help you to remember the symbols if you think that the triangle (the masked right ear

symbol) fits within the circle (the unmasked right ear symbol), and that an X fits in a box

.

This loss shows both ears on one audiogram.

What is the type of loss and extent of loss for each ear?

The right ear has a slight to mild loss in the low frequencies (250-500 Hz), above that point the loss slopes from moderate to severe.  The loss is sensorineural.

The left ear has a moderate loss through 500 Hz, and a moderately severe, sloping to profound loss above that point.

The audiologist would probably focus on the asymmetry between the ears, and might say:  “An asymmetrical, sensorineural loss was found.  The better right ear has a sloping loss, ranging from slight to profound.  The left ear thresholds

are worse for the low and mid frequencies, where the loss is moderate to moderately severe.”

Again, you are looking at test results for both ears on one audiogram, which is the most common format.

What is the type of loss and extent of loss for each ear?

Most patient have audiograms that are symmetrical; both ears have similar thresholds.  But that would be boring for you to interpret, so you will tend to see asymmetrical losses in this practice set!

The right ear has normal hearing until 1000 Hz.  In the high frequencies, the loss ranges from mild to moderate and is sensorineural.

The left ear has a mild to moderately severe mixed loss.  The loss is gently sloping.  

What is a “vibrotactile” threshold?

Sound can be felt if it is loud enough.  You know that you can feel the bass in loud music, for example.

When doing audiometric testing, the sound can sometimes be felt – either in addition to being heard or instead of being heard.

Some patients can tell you if it was a threshold of feeling or hearing, but most cannot make that discrimination.  When the sound is loud enough to be

potentially felt, then the audiologist would mark the threshold with a little “VT?” next to it.  If the patient reported “Oh, by the way, I felt that rather than hearing it”, it would be marked with a “VT” without a question mark.

Are vibrotactile thresholds more common when doing air-conduction or bone-conduction testing?  

Are vibrotactile thresholds found more often in the low frequencies or the high frequencies?

Bone-conduction.  The bone oscillator (aka bone vibrator) produces a mechanical vibration, so it is easy to feel.

Air conduction sounds can become loud enough to be felt, too.  However, they have to be much louder.  If using the newer, and generally preferred, insert earphones, it will take even louder sounds to be felt.  That is because the sound makes contact with a smaller area of skin.

The low frequencies are felt more readily than the high frequencies.  

What if the air conduction threshold were found to be 70 dB HL, and the bone conduction threshold were found to be 35 dB HL, but there was a “VT?” notation by the bone conduction symbol.  Would you: a.  Conclude that the loss is mixed b.  Conclude that the bone conduction threshold      is higher than 35 dB HL and call the loss sensorineural c.  Be unable to determine if the loss is mixed or sensorineural.

c.  We don’t have a valid bone conduction response – one that is definitely from hearing.  (If it hadn’t been vibrotactile, then yes, the loss would have been

considered mixed.)  But just because it is possibly vibrotactile doesn’t mean it wasn’t heard.  Or even if that 35 dB HL signal was felt, maybe if it had been turned up to 40 then it could have been heard.  So, we have uncertainty.  We

don’t know if it is a mixed loss or a sensorineural loss.  There is the possibility that the true bone conduction threshold (hearing, not feeling) will be near 70 dB

HL, so there is the possibility the loss is sensorineural.  We just can’t tell!

How would you interpret this audiogram?

There is a moderately severe to severe, relatively flat loss in this right ear.  A conductive component to the loss at 250 Hz cannot be ruled out; the threshold at by bone conduction may be vibrotactile.

There are two possibilities – either the bone conduction hearing threshold is at (or near) 35 dB HL, in which case there is a conductive component at 250 Hz and the loss is mixed – or the 250 Hz bone conduction threshold was just a threshold of feeling, and if you could have established the true hearing threshold it might have been near 60 dB HL, in which case the loss would be sensorineural.

Just looking at the audiogram, you cannot rule out a conductive portion to the loss at 250 Hz.  (However, other tests such as tympanometry and acoustic reflex testing would help make the determination.)  

What does a “no-response” symbol mean, and what do they look like?

A no-response symbol means that the audiologist presented the signal at that intensity, but the signal was not heard.

No response symbols have the appearance of the usual symbol, but then have an arrow off the bottom.  The arrow points to the left for right ear symbols, and to

the right for left ear symbols.  For example…

Describe the right ear’s hearing.

Here’s how an audiologist might explain this loss.

“The right ear has a highly unusual audiometric configuration, with an island of better hearing from 1000-3000 Hz, where the loss is mild to moderate.  Above and below this frequency range, the loss is much worse, moderately severe to severe.  While there is certainly a sensorineural component to the loss, the presence of a mixed loss cannot be ruled out.  Low frequency bone conduction scores are potentially vibrotactile, and thus are not necessarily an indication of cochlear reserve.“ Because of the configuration of  the loss the probability of this being a real conductive component is greater, but we cannot tell without examining the immittance test results (tympanograms and reflex data).

Give careful consideration to the left ear now, with special note to the bone conduction score at 4k Hz.

This is a precipitously sloping high frequency sensorineural loss.  Why can the audiologist say it is definitely sensorineural and not consider the possiblility of a 4000 Hz air-bone gap?  That takes some careful thinking.

Remember that an air-bone gap must be at least 15 dB to be significant.  The 70 dB HL bone conduction signal was not heard.  If the audiometer could have made the sound louder, perhaps 75 dB HL could have been heard.  That is the lowest threshold that is possible for this person.  If that happened, then the air-bone gap would only be 10 dB, and that would not be a “significant” gap.  Remember that slight gaps (like the left ear’s 10 dB air-bone gap at 2000 Hz, and the 5 dB bone-air gap at 250 Hz in the left ear) are not meaningful

Describe this audiogram.

Discuss testing of interoctave frequencies.

When is it needed, and has it been done correctly?

Should 3000 Hz be tested routinely?

The left ear has normal hearing in the low frequencies, but a mild, precipitously sloping to severe sensorineural loss in the high frequencies.  Again, while it looks like there is an air-bone gap at 4000 Hz, it is only 15 dB, and if that frequency could have been heard by bone conduction, it would have left at worst a 10 dB air-bone gap, which is not significant.

When there is a 20 dB or more difference between thresholds at octave frequencies, the interoctave should be tested.  For example, at 2000 Hz the threshold is 35 dB, and at 4000 Hz the threshold is 80 dB, so 3000 Hz should be tested, too.   750 Hz should have been tested as well.

Many audiologists routinely test 3000 Hz.  This is prudent because hearing handicap formulae require the 3000 Hz threshold.  Also, 3 kHz is an important threshold to know when fitting a hearing aid.  Noise-induced hearing loss can show up as a dip in hearing at this frequency, so it is often tested for that reason too.  

Describe this audiogram

This audiogram shows an audiometric configuration that is consistent with noise trauma.  Noise-induced hearing loss is most severe in the range of 3000-6000 Hz, and is sensorineural.  Note that the right ear had poorest hearing at 3 kHz, while the greatest loss is at 4 kHz in the left ear, which illustrates the importance of testing 3000 Hz.

Both ears have normal low and mid frequency hearing.  The right ear has a mild to moderate high frequency sensorineural loss; the left ear’s slightly more severe sensorineural loss also ranges from mild to moderate in severity.  Interpret this last audiogram.

The right ear in this audiogram has a precipitously sloping hearing loss above 250 Hz, where the loss ranges from mild to profound.  The loss is most likely

sensorineural, but a conductive component restricted to 4000 Hz cannot be ruled out.  There is a possibility this loss is mixed.  Note, the gap between the bone

conduction limit symbol at 4kHz and the air conduction symbol is 25 dB HL.  If the patient could have been tested at 75 dB HL, perhaps that would have been

heard.  If that had happened, then there would be an air-bone gap of 20 dB HL, which would have been significant. (However, true air-bone gaps that occur only

in the highest frequencies are pretty rare, so if you had to bet, guess sensorineural!)

  Note that, although there is a 25 dB gap between 250 and 500 Hz there is no

interoctave frequency that can be tested.  Audiometers do not have an interoctave frequency between 125 and 250 or 250 and 500 Hz.  The dashed lines

on the audiogram note the testable interoctave frequencies.