In terms of our ability to communicate with others, hearing is our most critical sense.
Even relatively mild hearing loss can seriously disrupt how we interact and connect with others. Negative effects of hearing loss on our social, mental, and physical health, can be significant and overall quality of life can plummet. Healthy hearing requires a number of processes in the inner ear and brain to work properly in order to correctly interpret the sounds you hear. Inner-ear problems, or ear problems in general, can prevent crucial pieces of sound information from reaching the brain, leading to confusion and an inability to understand what is being said. Commonly, a problem in the outer and/or middle ear is referred to as a conductive hearing loss, while inner-ear problems and/or brain-processing difficulties are referred to as sensorineural hearing loss. These are two distinct types of hearing loss with differing treatment methods.
Why Binaural Hearing is Important
Binaural hearing refers to the brain’s ability to integrate information from both ears at once, which greatly improves overall communication and the ability to understand where sounds come from in relation to your body’s position (localization). Hearing with both ears is critical to understanding speech in noisy, complex environments.
Common Types of Hearing Loss
- Sensorineural Hearing Loss (SHL): The most common type of hearing loss, SNHL is typically the result of damage to the delicate hair cells in the inner-ear organ (the cochlea) that are responsible for picking up sounds. When these hair cells — or the nerves they connect to — are damaged or destroyed (commonly by repeated exposure to loud noise), hearing becomes more difficult. Due to the anatomy of the ear, SNHL typically affects the high frequencies first, however this can vary. SNHL is generally not medically treatable. The damaged hair cells do not grow back. The most common treatment for this type of hearing loss is amplification via hearing devices.
- Conductive Hearing Loss: This type of hearing loss is due to damage to or from a malfunctioning outer or middle ear system. Common causes of conductive hearing loss are Otitis Media (middle ear infection) or a blockage in the outer or middle ear from ear wax. Swimmer’s Ear (infection of the ear canal) can also create a blockage resulting in hearing loss. Conductive hearing loss is typically medically treatable and reversible once the infection or blockage clears, or once necessary surgery is performed.
- Mixed Hearing Loss: Individuals with mixed hearing loss suffer from a combination of both SNHL and a conductive hearing loss. Hearing may improve after the conductive portion of the hearing loss is resolved through medical treatment, but may not return to normal levels due to the sensorineural component.
- Unilateral Hearing Loss: Hearing loss that occurs in only one ear is referred to as unilateral hearing loss. This can be present at birth, may happen spontaneously, or can occur over the course of several days (referred to as sudden hearing loss). Unilateral hearing loss may delay or otherwise affect speech and language development. Those with unilateral hearing loss will also have difficulty identifying where sounds are coming from (localization), understanding speech in noisy situations, and hearing from longer distances. Children who are born with unilateral hearing loss are far more likely to repeat a grade. They can achieve success academically, economically, and socially by focusing on communication development. CROS (contralateral routing of sound) hearing aids are available for those with unilateral hearing loss. These aids use a microphone in the non-hearing ear to wirelessly transmit the sound to a device placed in the hearing hear allowing the person to pick up sound from both sides of their body.
- Sudden Hearing Loss: Sudden hearing loss occurs either entirely or partially within a 24 -72 hour period — or immediately. The degree of loss varies and it is often accompanied by head noise and/or vertigo. Sudden hearing loss is most often experienced in only one ear and frequently occurs a week or so after experiencing another illness such as a head cold or other viral infection. Sudden hearing loss is often misdiagnosed as a middle ear infection, but middle ear infections occur typically in both ears. It is important to have your hearing tested right away and receive medical treatment, most typically steroid treatment, within 72 hours in order to increase the chance of recovery. That is why it is important to diagnose it correctly from the outset.
- High-Frequency Hearing Loss: Due to the anatomy of the inner ear, damage to the high frequencies usually occurs first. The most common complaint from those with high-frequency hearing loss is difficulty understanding speech in the presence of background noise. It is important to recognize that hearing someone and understanding them are two different things. High-frequency hearing loss typically results in loss of clarity of speech which makes speech difficult to understand even if it can be heard, especially in more difficult listening environments. Often in quiet situations, the listener has minimal difficulty understanding who they are speaking with. High-frequency hearing loss is frequently caused by exposure to loud noise, toxic medications, and the aging process.
People with high-frequency hearing loss will have difficulty differentiating words that sound alike, especially words that contain S, F, SH, CH, H, TH, T, K or soft C sounds. These consonants are quieter and are in a much higher frequency range than vowels and other consonants.
The loudness of sound is measured in decibels. Pitch is measured in frequency of sound vibrations per second. A deep voice has a low pitch and frequency, whereas a child’s voice has a higher pitch and frequency.