A "sign" is what a health care provider can detect with testing or a medical exam (and a "symptom" is what you notice but can't necessarily be measured). To look for the signs of hearing loss, a hearing care provider will generally start with questions about symptoms you're experiencing, and then conduct a formal hearing test to see how well you hear beep-like sounds (known as a pure-tone test), speech in noise and other sounds. Your hearing is then plotted on an audiogram that shows the extent of your hearing loss in both ears. Here's how to know if you need your hearing tested.
The most common type of hearing loss is sensorineural hearing loss, which is caused from damage to the delicate hair cells in the inner ear and/or the nerve pathways that deliver sound to your brain. About 90% of people with hearing loss have this type, and it has a wide range of causes.
Volume and clarity are affected. Sensorineural hearing loss is usually gradual—you don't wake up overnight not being able to hear. Instead, you slowly lose the ability to hear. Both how loudly (volume) and how clearly (clarity) you perceive sound are affected. You might also experience a phenomenon known as recruitment, which causes some louder sounds to be uncomfortable to listen to. For example, you once loved fireworks shows, but now find the booming sounds nearly unbearable.
Similar to high-frequency hearing loss, noise-notch hearing loss means you can't hear certain high-pitched sounds very well (such as children's voices). But unlike high-frequency hearing loss, you may still hear very high-pitched sounds (birds or beeps). This type of hearing loss is associated with noise-induced hearing loss, especially loud gun blasts. For example, hunters who develop shooter's ear often have a noise-notch pattern of hearing loss.
Rarer still, reverse-slope hearing loss is essentially the opposite of high-frequency hearing loss. Symptoms include finding men's voices harder to hear than women's or children's voices, struggling to hear people on the phone but not so much during face-to-face conversations, and inability to hear environmental sounds that are low-pitched, such as the bass in music or thunder. A person with reverse slope hearing loss also might seem unusually sensitive to high-pitched sounds, too.
In rare cases, a person can develop sudden hearing loss, usually in one ear. It may be conductive or sensorineural. The symptoms and signs are generally pretty obvious—you suddenly can't hear well out of one ear. But if you have a bad cold or ear infection, it may be hard to tell if it's just temporary congestion or actual hearing damage from the virus or bacteria. In some cases, people hear a loud pop and then lose their hearing. The affected ear may feel stuffy, or "full," and a person may feel dizziness or hear ringing in the ear. Because prompt treatment is key, act fast if you experience sudden hearing loss.