When we use the word “normal” in hearing, it is mostly used to denote when hearing is not significantly impacted by hearing loss. However, determining exactly what that threshold is can actually be quite confusing. Part of the complexity here lies in considering the range of ways in which hearing damage can manifest in our hearing patterns. Let’s take a look at what the baseline is for “normal” hearing as well as some different configurations of hearing loss.
Establishing What Is “Normal”
You may be surprised to learn that our benchmark for normal hearing was set at the 1933 World’s Fair. Setting out to establish what “audiometric zero” was -the lowest threshold of human hearing- researchers there tested the hearing ability of thousands of fair attendees. The findings of the World’s Fair were developed into what we now know as 0dB (the softest sound level detectable by the human ear) as well as the thresholds of hearing loss levels, such as normal hearing and mild, moderate, severe and profound levels of hearing loss.
Commonly, these hearing loss levels are determined by the threshold of one’s hearing ability. Mild hearing loss indicates that the minimal volume needed to hear a sound is in the range of 26-40 dB rather than 0dB. Moderate hearing loss means difficulty detecting sounds that are below the range of 41-55 dB while the threshold for moderately severe hearing loss is between 56 and 70 dB. Severe hearing loss means that sounds are only noticed without difficulty if they are quite loud, in the range of 71-90 dB. Profound hearing loss applies to all hearing problems that make it hard to hear sound at volumes below 90 dB.
Configurations of Hearing Loss
The level designations for hearing loss are very useful in defining a person’s hearing difficulty, but there is also another factor at play. Without factoring in hearing losses, human hearing can usually sense sound frequencies from 20 Hz (hertz) to 20 kHz (kilohertz), with human speech usually falling within the range of 100 Hz – 5000 Hz. Hearing loss is usually specific to certain frequencies of sound – often very high or very low frequencies, like birdsong (high) or rumbling thunder (low). Frequencies in the middle of our “auditory spectrum” are less likely to be affected, but can still demonstrate hearing loss.
When you get your hearing examined, a tonal test will be used to see how well you can detect sounds at varying frequencies and volumes. This information will be used to plot an audiogram, a diagram of your hearing ability. The way your audiogram is analyzed works to take into account where you have hearing difficulty, how severe it is and how it affects your lifestyle. Hearing loss seldom blankets the entire auditory spectrum equally and even hearing loss in a small frequency range can limit the way we comprehend speech and respond to the world around us.
For example: for many people, the first sign of hearing loss is a difficulty in hearing high frequency sounds and speech, while their hearing for mid-range and lower frequencies does not demonstrate significant impairment. However, because high-frequency hearing loss can drastically limit our perception of speech, treating hearing loss with hearing aids can boost hearing for high frequency sounds and re-introduce them to how we hear.
When you work with a hearing specialist, they can connect you with hearing aids that are especially programmed to enhance your hearing at the specific frequency ranges where you need it most. Personalized hearing aid programming offers you the fullest, most natural way of correcting hearing loss, as challenging sounds are digitally boosted to make them more easily perceptible. Working with a hearing specialist gives you a finely-tuned solution to hearing loss that compensates for your hearing challenges exactly in the areas you need.
The configuration of your hearing loss is unique to you, which is why there truly aren’t “one-size-fits-all” hearing aids. Hearing aids that are tailored to the shape of your ear canal and the configuration of your hearing loss are the most effective and nuanced way to treat hearing loss. If you have noticed a change in your hearing from what is “normal” it is time for your next hearing exam – and we’re here to help. Contact us today!