David Mason R.H.A.D Hearing Aid Audiologist Ampleforth, York.    Tel: 0800 612 7 812
0800 612 7812

David has now retired and has
handed over the business to
Mr Robert Donnan RHAD.

Please be assured that his service and commitment to his clients are in direct parallel with our own. He has recently opened a branch in Fulford, York and has a number of other highly useful resources that you may find useful in the future. This includes Micro suction.

You can have every confidence in his service and I'm delighted to say that he always treats people with consideration and commitment. If you are interested in the latest hearing instruments he will only be too pleased to organise a free trial.

David Mason - August 2016

www.rjdhearingcare.co.uk

York Hearing Practice, 92 Main Street, Fulford, YORK YO10 4PS

Freephone 0800 612 7812



Hearing tests


What happens on a hearing test?


Could it be the last hearing test you had was at school? Whereas an eyesight test is now expected to be routine, a hearing test, if looked on as an unknown quantity, could create delay or a feeling of 'wait and see'.

In order to prepare you for your first visit and address any worries you might have, I would like to provide you with some important information to help you understand this process.

You should schedule about an hour or so for your first visit. If possible, it is a good idea to ask a relative or friend to accompany you. Many people feel more secure that way. A friendly face by your side is particularly helpful if there are communication issues. I personally find this an essential and preferred part of my everyday testing and certainly makes it more proactive.

Your medical history

Before beginning with the actual hearing test you will be asked some questions about your medical history including:

  • Noise levels you have been exposed to, i.e. are they work/sport related?
  • Family history
  • Possible physical damage to your ear(s)
  • Past illnesses or other conditions that may have affected your hearing; and
  • Medications that may have affected your hearing.

Understanding your medical history and talking about the actual situations you are having difficulty in helps enormously in determining a course of action to find a solution to your hearing loss.

Looking into your ear

healthy ear drum After recording your medical history, your ear will be examined using an instrument called an otoscope, a cone-shaped instrument with a light on one end - it helps your audiologist view the inside of your ear canal - the image you see here shows a normal, healthy eardrum.

With an otoscope, your professional can determine if there are any abnormalities in your ear canal or with your eardrum. This includes a number of ‘referable’ conditions that we have to, by law, advise you on. If we come across any of these, you should be asked to see your GP. Please be aware that a private hearing aid audiologist is under very strict guidelines from the Health and Care Professions Council - our governing body (http://www.hpc-uk.org/).

Pure tone test

After your ear examination the following simple procedures will be carried out:

Pure tone testing helps determine the threshold at which you hear different frequencies. For the pure tone test, you will be asked to place a pair of headphones over your ears.

The headphones will deliver a series of tones into your ears. An audiometer electronically generates the ‘pure tones’ which will vary in pitch and volume.

Whenever you hear these tones you will either raise your hand or push a button to indicate that you hear it. This shall be individually carried out on both ears.

For the next set of pure tone tests, a small bone conductor is placed behind your ear very similar to an Alice band. The bone conductor transmits sound through bone vibration to the cochlea of the inner ear, bypassing the middle and outer ear.

This set of pure tone tests helps determine your type of possible hearing loss. Tip - I am coming across more and more examples of this vital part of the test being left out from organisations and even some hospitals. If for any reason it is not included in your test, ask why. It's called bone conduction testing.

Why is this important? If the results show what we call a conductive loss, i.e. some kind of blockage (or other occlusion/condition) in the outer or middle ear, then this should be referred to your GP as it may not only pre-empt the necessity for a hearing aid but may lead to some corrective treatment if your GP decides to refer you an ENT (Ear, Nose and Throat) consultant.

Speech tests

After the pure tone tests, you may be given some speech tests.

For the speech tests, we are trying to determine the level at which you can detect and understand speech. You will hear a series of words that you will be asked to repeat. Some of the words will be 2-syllable words, and the words will become softer as the test proceeds.

Next, you will be asked to repeat a set of 1-syllable words; however, the volume of these words will stay the same. Depending on the results of the pure tone and speech tests will determine whether any other further testing may be necessary.

Introducing the Audiogram: a picture of your hearing thresholds

The audiogram is a picture of how well you hear. It shows the softest sounds you can hear at different pitches or frequencies.

audiogram-chart-1 This is known as the threshold hearing level for each frequency. In the audiogram right, look at the left-hand column. As you move down the column, the sounds are getting louder and louder.

Now take a look at the row of figures on the top (250, 500, 1,000, etc.). As you move to the right, the sounds are increasing in pitch, like the keys on a piano.

We say they are increasing in frequency or cycles per second and they are measured in units called hertz (Hz). Thus, a sound that measures 5,000 hertz is much higher pitched than a sound that measures 250 hertz.

Children can hear sounds up to about 20,000 hertz, but as we grow older, we gradually lose our ability to hear higher-pitched sounds.

The subject above has a 10 dB threshold hearing level for most sounds, meaning he can't hear sounds below 10 dB in volume.

audiogram-chart-2 For higher-pitched sounds above 4,000 Hz, his threshold hearing rises to 20 dB. Any loss up to about 20 dB is considered normal.

Audiogram showing a hearing loss

What is the significance of this audiogram? What can it tell us about this person’s ability to understand speech? We'll see in the next section.

Hearing loss and speech intelligibility

In the audiogram right, you can see where our basic speech sounds lie when engaging in normal conversation.

Two things are important to recognize. For the most part:

    audiogram-chart-3
  • Consonants are higher pitched than vowels (they lie more to the right on the chart).
  • Consonants are spoken more softly than vowels (they lie higher on the chart, in the lower decibel ranges).

These factors play a big role in our ability to understand speech. For one thing, the great majority of people with hearing loss lose it in the higher frequencies, where the consonants lie.

This is especially true of hearing loss due to aging. Generally, people hear the vowels but not the consonants. In addition, since consonants are spoken more softly, they tend to get drowned out in background noise.

Remember that every 10 dB increase or decrease doubles or halves the perceived loudness of the sound.

Keeping that in mind, we can see that the ‘a’ at 40dB sounds twice as loud as the ‘p’ (30dB) and four times as loud as the ‘th’ at 20dB. The ‘e’ (50dB) sounds twice as loud as the ‘a’, four times as loud as the ‘p’, etc.

So your typical person with hearing loss will have trouble hearing the consonants in the first place. He may be hanging on by a thread.

Add a little background noise and he may lose them altogether and, since we're on the subject of speech intelligibility, there is one more fact to consider: consonants convey most of the word information; they are much more important to speech intelligibility than vowels. Try this exercise: write down any paragraph from the magazine or book and then take all the vowels away and see if you can make sense of it. Chances are you will be able to read it. Now take the consonants away and you'll see what I mean.

If you, or someone you know, have ever said, ‘I can hear the words, I just can't understand them’, this is the reason why. If you, or someone close to you, complains about speech not being spoken the way it used to be - whether that is television, radio or having a chat in your living room, you can be assured there is a high chance they are ‘missing’ some of the top end frequencies.

Another way to look at it, is that it is like a piece of music; if you take the trebles away you alter the qualitative sounds so that it sounds ‘bassier’ to the listener. By the way, this is another area where the hard of hearing suffer if they have a love for music. Sometimes it's very difficult to explain that music just doesn't sound the way they remember it.

One additional characteristic of consonants: they act as breakpoints, separating syllables and words from one another. If we can't hear the consonants clearly, the words seem to run together and people sound like they are ‘mumbling’. Since women and children have higher-pitched voices than men, it seems like they mumble more.

Putting it together

1. Consonants are infinitely more important than vowels in understanding speech.

2. Consonants are spoken more softly than vowels, and they tend to be drowned out in noisy environments.

3. Consonants are higher-pitched than vowels and most hearing loss occurs in the higher frequencies.

It's harder for people with hearing loss to hear the consonants in the first place, and noisy environments just make it worse. No matter how hard they try, they are just not getting it all.

The result is fatigue, frustration, and an increasing reluctance to engage in social situations.

audiogram-chart-4 To illustrate how a hearing loss affects speech comprehension, we will now superimpose the audiogram of the person with moderate/severe hearing loss over the speech zone.

The screened area lies below the subject's threshold of hearing, i.e. what he can’t hear.

As you can see, in a normal conversation this person will simply not be able to hear many of the consonants. The other person will have to speak considerably louder to be understood.

That is, he will have to push the loudness of his speech above the subject's threshold of hearing. This obviously puts a strain on everybody involved.


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