Hearing Loss

Hearing Loss What does it mean?

When speaking about hearing loss, a lot of people believe that if you have a hearing loss that means you are deaf. This is not the case. Think about your eyes, if you wear glasses does that make you are blind? No, it just enhances what you can already see. Hearing aids give you the same assistance, they enhance what you can already hear.

So what is hearing Loss?

Simply put, hearing loss effects your ability to hear and results in your hearing being reduced. A hearing loss will make it more difficult for you to hear speech as well as other sounds overall.

To give you a better understanding look at the picture below. This is a standard hearing loss otherwise known as presbyacusis (age related hearing loss).

The Graph Explained

The first thing to notice is the vertical axis, this is the sound level in decibels (dB). Along the horizontal axis you have the Hertz (Hz). You can then see the red and blue lines/points. These are the quietest points that have been heard by the patient (this is a fictional patient). You can see that the graph (audiogram) has different levels of severity. This indicates this patient has a serve sensorineural hearing loss.

Now unless you are currently studying audiology or have had hearing aids for a number of years, this may be difficult to understand fully. You can go back to the how hearing works page to grasp the concept further.

Looking at the graph, if you imagine the 20dB on the vertical axis being the sound of a whisper and 120dB being close to the sound of jet engine. Along the horizontal axis, if you imagine a piano with the low sounds on the left and high on the right. Finally, the points on the graph that you can see are the quietest points at which the patient is able to hear. For example: At 250Hz, the patient can hear the sound at 10dB. In contrast, the 8KHz can only be heard at 80dB. Have a look at the image below and we will explain it in more detail.

Here we have the hearing loss overlays

The first overlay you should notice is the grayed-out area. This is the area of hearing that no longer works, essentially this part of the hearing is dead. We then have the speech letters, these are some of the fundamental speech components. As you can see this person would be missing the higher pitched ‘f, th, s, sh and k’ sounds within speech. It is especially important when it comes to having conversation in a noisy environment. You can see with these letters, the lower tones can be heard perfectly well. When this happens, the patient will be fine in a quieter environment as there normally are not too many distractions. However, as soon as a background noise is introduced you will find this patient will start to struggle to hear clearly.

Why will the patient struggle?

The reason behind this is due to those higher pitched sounds we mentioned before. They are not able to give this person the clarity of sound. The reason for this is because higher pitch clarity sounds are no longer working correctly. Finally the little box that looks a little like a smiling mouth, is called a ‘speech banana’ (Please see graph for reference).

What the speech banana shows is that the

 part inside that box is where the majority of speech tones are available. For example if someone is quietly spoken, they are more likely to have a higher pitch of voice. The voice would sit close to ‘f’ in the image above, that would then make it very difficult for this patient to hear the person speaking. In contrast a big bellowing loud voice would sit closer to the ‘b, d’ letters. This would mean that this patient would not struggle to hear this person at all, depending on the situation.

Final thoughts,

As a basic explanation of hearing loss’, this will hopefully give you more insight to what hearing loss is. However, if you want a more in depth reason behind hearing loss please carry on and look to the next pages.