Category: How to

Ear Pathologies and Audiograms: Part 1 (Frequent Offenders)

Our BSA Audiometry course is a great place to start when you wish to learn how to do a basic audiogram. For those of you that are training to be an audiologist then we offer a masking course too. Please look at our training calendar for dates for these Training Calendar – TJ Audiology Training. We will soon be offering masking theory as an online tutorial, through a portal accessed from our webpage (watch this space)

So, you understand how to do an audiogram but what do the results mean? What are they telling me? When I started audiology 30 years ago, we had a great text book by James Jerger called Clinical Audiology (easier to read than Katz!!) that gave you both audiograms and tympanograms for different types of hearing loss and this helped give you a starting point. Its long out of print now. However, we still regularly use his classifications for our tympanograms.

I am not going to explain an audiogram graph and the different symbols (AC: Air Conduction and BC: Bone Conduction) and degrees of loss, I am assuming that you already have this knowledge! Let’s, start simple and then get more complex (because there is so much information to give this will be an ongoing series). Remember the list is not exhaustive and you will get people that don’t fit the normal pattern. This is why the BAA Onward referral guidance – British Academy of Audiology |British Academy of Audiology has red flags for referral onto ENT, include other audiological issues such as dizziness, tinnitus and facial palsy, not just the audiogram.

Normal Hearing

Please note if hearing is normal but there are other red flags such as dizziness or unilateral or pulsatile tinnitus onwards referral will be required (if these red flags are present for any of the hearing loss below then onwards referral to ENT will still be needed). You would generally expect normal tympanometry results.

Sensorineural Hearing Loss

Sensorineural. The triangles which are the bone conduction results are within 10dB of the air conduction thresholds indicating that this is a mild to moderate sensorineural hearing loss. You would generally expect normal tymps with this loss.

Noise Induced Hearing Loss

With a noise induced loss you will see a dip between 3-6kHz and then upwards improvement and the BC results within 10dB of the AC (only AC shown on these examples). However, as a client ages, then you add an age-related loss on top or increasing noise exposure (as shown in the 2nd graph) then the proportions will change. You would generally expect normal tymps.

Glue Ear

Glue ear is often found in children under the age of 7-9. The eustachian tube is narrower and flatter than in an adult. Children under this age are more likely to suffer from Glue ear/Otitis Media as the eustachian tube is unable to drain as effectively.

The audiogram with show reduced hearing through the headphones (AC), but the bone conduction results (BC) will be within the normal range. (20db or less if there is no underlying sensorineural hearing loss). You will either have a flat tymp or negative middle ear pressure for the reasons explained below.

The audiogram gives a flatter presentation when the middle ear is so fluid filled that both mass (how much mass is there in an object) and stiffness (how stiff the object is) are being affected. Stiffness affects the lower frequencies and mass the higher frequencies. If there was some draining or improvement in the glue ear than you would see the higher frequencies improve. (as there is now less mass)

Tympanosclerosis

Tympanosclerosis is scaring on the eardrum. The scarring occurs either from perforations that have healed or from having had grommets. The amount of scarring will be dependent on the amount of irritation and bleeding that has occurred during these events.  Scarring will cause the eardrum’s movement to be stiffer. Stiffness as we said earlier will affect the lower frequencies as shown in the audiogram. Tymps may show restricted or shallow movement.

Perforation

Remember this is an example audiogram and your audiograms may differ . In this case the client already has an underlying sensorineural hearing loss (the BC is out of the normal range).  The degree of conductive component of the loss will be dependent on how the perforation affects the transmission of sound from the middle ear space to the cochlea. As for tympanometry you will have either a flat tymp with a large canal volume or you will not be able to obtain a seal. Below is another audiogram example for a perforation where the squiggly lines (masked BC are within normal and the AC is down).

How to write an audiology report for other medical/allied health professionals

This may seem a strange blog to write for an audiology training provider. However, if we are training you to provide an audiology service; then at some point your audiology service will need to write a report to someone, either to inform them of what you have done or to refer onwards for further assessment/intervention.

Once you have informed the person who you are sending the report to then the onus of responsibility is no longer fully on you. Asking a client to see their GP, ENT, audiologist, paediatrician or other allied health professional with your verbal direction of what is needed, isn’t good enough. The client or the other individual (e.g. GP) may not heed this request. A court of law will indicate that a verbal request isn’t sufficient; even if you have written in your notes that you made one and specified what was required .

Remember you will need approval from your client to write the letter as well. You cannot send a referral letter without their consent.

Who to write to?

Unless you have direct access to ENT or an audiology department or provider (UK) then all letters should be directed to your GP who will refer onwards to other professionals such as neurology, psychology etc. You may be able to directly send a report to other allied health professionals such as speech therapists. Remember to check what the local protocols are if you are NHS and if you are a private practitioner you can often directly refer to other private health professionals such as ENT and speech therapy, however for example neurology will require a GP letter even for private appointments.  See below how the start of your letter should be.

Dr ………

Address…………

……………………

……………………

                                                                                                                                                                                Date:

Dear Doctor

NAME:

ADDRESS:

DOB:

NHS No: (if you have it)

Then start with a bit of history. Why they had attended the appointment and the date of the appointment. What is the problem they came for? Medical and otological (ear history) that is relevant to the appointment. For example for a hearing test appointment

 ‘was seen seen on 12.11.24 due to concerns about their ability to hear, particularly on the left ear. They have bilateral tinnitus (non pulstatile) for some years, but have habituated to this. They do not have any vertigo and there is no family history of hearing loss or previous history of ear problems .As you know they had a stroke in JUNE 2016, and have indicated that speech now takes them longer to process.’

You always need to describe any ear related history, is there any balance issues if so describe the issues that they have (remember try and be concise as the GP or ENT) will want a succinct easy to read letter). Do they have tinnitus, if so is it one ear or both. Is it pulsatile or not? If it is unilateral or pulsatile both of these are red flags and referral onto ENT for investigation is required. Is there any family history of ear problems or have they had any ear problems such as ear infections , ear nose or throat operations etc? Also add any relevant medical history that you feel may be important for them to know or acknowledge may be relevant.

Next describe what you saw and did

‘Otoscopy showed both ears have a slight amount of non occluding wax. It is worth noting that both ear are fairly narrow.

Pure tone audiometry showed a bilateral mild to moderate sensorineural hearing loss with right thresholds slightly worse than left.  (inserts were used due to narrow canals). Speech testing was consistent with the hearing test, indicating when speech words/sentences where presented loud enough to compensate for the hearing loss the client was able to understand speech words well. Tympanometry showed normal middle ear function/Movement in both ears.’

The above example is for a hearing test appointment. If it is a balance or tinnitus appointment you need to describe the test you did. What it was you were looking for; what is the normative data for the age of the person you have seen. Or what the numbers mean when compared to the normative data.  Remember that your reader may not have the knowledge that you have.

After you have described what you have found. They need to know what you want them to do and what you are doing.

‘ The above findings indicate an asymmetry/difference between left and right ears. According BAA Onwards Referral Guidelines this difference between thresholds requires onwards referral to ENT to investigate the cause of this asymmetry’.

…. has indicated that they would like to go ahead with NHS hearing aids and this is now in process.

Of course, finish with yours …. and your name and qualifications and if the letterhead doesn’t have contact details, then add these to your name.

Remember  to add the audiogram either in the body of the letter or specify at the bottom that it is attached to the letter. For other letters if you have images, attach these as well or indicate that they will be attached electronically, if you are emailing the letter. Under all your details if you are sending a copy to the client or anyone else then add a CC: with the name and relevant details: eg clients name or a consultant’s name and their hospital.

If you are emailing remember that you must use an encrypted email and most professional organisations will also have encrypted email (I often state this in my email) and ensure that you have the correct email address before sending. It is an information governance breach if it is sent to the wrong address.

For BAA Onwards referral guidelines please Onward-Referral-Guidance-for-Adult-Audiology-Service-Users-Sept-23.pdf