Understanding Hearing Loss
A hearing loss, or hearing impairment, is when your hearing is not within the normal predisposed range. In order to understand this, it might be helpful to understand a hearing test and what it measures.
An audiogram is a graphical representation of what you hear. There will be two axes: one represents the different frequencies tested in Hertz (Hz) and the other represents the level/volume in decibel (dB). Based on the test results, we will plot the softest sound that you hear at each specific frequency, which is called the threshold. Responses obtained from the right ear are plotted by using an “O” while responses obtained from the left ear are plotted with an “X”. To make sure you understand this concept, let us look at the audiogram below. The threshold for the right ear at 250Hz is 25dB, at 2000Hz it is 40dB and at 8000Hz it is 65dB.
Normal hearing is 0dB for all the frequencies, but we take the range between -10dB to 25dB as an acceptable one. That means that any threshold where the number is 25dB or greater is considered to be a hearing loss.
To give you an idea of how loud things are, below is a list of various sounds and their corresponding decibel levels.
0 dB – Threshold of hearing
20dB – Rustling Leaves
30 dB – Quiet Whisper 3 feet away
40dB – A Quiet Home
50dB – A Quiet Street
60dB – Normal Conversation
70dB – Inside a Car
75dB – Loud Singing 3 feet away
80dB – A Car 25 feet away
88dB – Motorcycle 30 feet away
90dB – Foodblender 3 feet away
94dB – A Subway (inside)
100dB – A Diesel Truck 30 feet away
107dB – A Power Mower 3 feet away
115dB – Pneumatic Riveter 3 feet away
117dB – A Cain Saw 3 feet away
130dB – A Jet Plane 100 feet away
“Throughout the years, I have had many patients tell me that their hearing is normal for their age. There are no age specific values for normal hearing. You either have hearing loss or you don’t.”
Bernice A. McKenzie, Au.D.