Hearing Loss

Signs & symptoms

听力损失主要有三种类型:

Sensorineural hearing loss

Permanent hearing loss occurs when inner ear nerves become damaged and do not properly transmit their signals to the brain. Those who suffer from this condition may complain that people seem to mumble or that they hear, but do not understand, what is being said. The aging process is a very common cause of sensorineural hearing loss. As we get older, the inner ear nerves and sensory cells gradually die. 这种情况通常不能通过药物或手术治疗. In most cases, the symptoms can be significantly minimized with hearing aids.

除衰老外，感音神经性听力损失还可能由以下原因引起:

• Injury
• Excessive noise exposure
• 病毒感染，如麻疹或腮腺炎
• 耳毒性药物，也就是损害听力的药物
• Meningitis
• Diabetes
• Stroke
• High fever
• Meniere's disease
• Acoustic tumors
• Heredity

Conductive hearing loss

这些障碍可能是暂时的，也可能是永久性的. 它们是由外耳或中耳的问题引起的, 是什么阻止声音到达内耳呢. People who experience this condition may find that voices and sounds appear faint. Many forms of conductive hearing loss can be helped medically or surgically. 这种情况的一些常见原因包括:

• 耳道或中耳感染
• Fluid in the middle ear
• 鼓膜穿孔或瘢痕
• Wax build-up
• Unusual growths or tumors in the ear
• Otosclerosis, a condition in which there is an abnormal growth of bone of the middle ear. This bone prevents structures within the ear from working properly and causes hearing loss. For some people with otosclerosis, the hearing loss may become severe.

Mixed hearing loss

Some people have a combination of both sensorineural and conductive hearing loss.

Hearing loss is often gradual and not immediately noticed by the person affected. Sometimes friends or family will notice a person's hearing problems before the person with the hearing loss recognizes it. For instance, family members may complain that the person with hearing loss listens to the television or radio too loud and often ask them to repeat what they've just said. Or, that the person with hearing loss doesn't answer the telephone or doorbell because they didn't hear it ringing.

Although each person may experience symptoms of hearing loss differently, 一些最常见的症状可能包括:

• 听不清别人说的话. People may seem to mumble and those experiencing hearing loss may not hear all parts of a conversation. For instance, someone with hearing loss may miss the essence of a story or punch line of a joke that someone just told.
• 经常要求重复或澄清.
• Tendency to need to stare at people when they are talking in order to make it easier to understand what they are saying.
• 在一天结束的时候，因为拼命听而感到疲劳.
• Avoidance of social situations because of difficulty following conversations in noisy environments.
• Tendency to bluff when not hearing someone because of the fear of asking them to repeat themselves.

Diagnosis

虽然听力损失在成年人中很常见, particularly those over age 65, 这种情况在老年人中经常被诊断出来. 听力损失会极大地影响一个人的生活质量. Therefore, if hearing loss is suspected, it is important that the advice of a doctor specializing in diseases and conditions of the ear, known as an otologist, otolaryngologist, or ear, nose and throat doctor, 是为了做出明确的医学诊断. The ear specialist also will work in close cooperation with audiologists, specialists in hearing disorders.

There are a variety of tests available to accurately diagnose the type and severity of hearing loss. These include:

• 空气传导，常规或标准听力学. This test is commonly used to measure the hearing of adults and older children. A range of test tones, 从低频到高频(被认为是“音高”), 是通过戴在耳朵上还是双耳内的耳机传输, 病人被要求举手示意, 当你听到每个声音时，按下按钮或口头回应. This testing determines the very softest signals you can hear at each of the presented frequencies, 并指出听力可能受损的频率区域. 声音必须越响才能被听到, the greater the degree of hearing loss at that particular frequency or frequencies. The frequencies tested are those important for hearing and understanding speech and other environmental sounds.
• Bone conduction. If testing reveals a hearing loss, another type of headset, a bone vibrator, is used to determine hearing by bone conduction in order to determine the type of hearing loss. This device sends sounds directly to the inner ear, bypassing the outer and middle ear. 如果声音通过骨传导听得更清楚, the hearing loss is conductive in nature and is likely located in the outer or middle ear. If the sounds are heard equally well with the earphones and the bone vibrator, 听力损失本质上是感觉神经性的. A combination of conductive and sensorineural hearing loss also may be present; this is called a mixed hearing loss.
• Word recognition. In addition to tests with tones, word recognition testing is usually performed to evaluate the ability to discriminate differences between the speech sounds of various words, and how clearly the words are heard. 在这个测试中，你会被要求听和重复单词.
• Acoustic immittance. These tests are used to assess the status of the middle ear and related structures. 一种声阻抗测试叫做, tympanometry, measures the movement of the eardrum to see if it moves normally when pressure changes are applied. Restricted eardrum movement could indicate a problem with the eardrum or middle ear structures. Acoustic reflex testing, a method of determining how the middle ear reacts to loud sounds also might be tested.
• Otoacoustic emissions (OAEs). oae用于评估耳蜗的功能. 当听力正常或接近正常时，通常会出现耳聋, 当耳蜗出现问题时，它们就会消失.
• Auditory brainstem response (ABR). ABR is a procedure used to measure hearing sensitivity and determine if the neural pathways within the brainstem are transmitting sound properly. 这个测试是用来排除听觉神经问题的. Brainwave activity in the auditory centers of the brain is recorded in response to a series of clicks or tones presented to each ear. During this procedure, electrodes are placed on the head to detect the electrical response of the brains to sounds presented while you rest or sleep. 电极不会引起疼痛或不适.

Treatments

听力损失有几种选择, 从医疗到监听设备, such as hearing aids. 治疗取决于听力损失的原因和严重程度. For age-related hearing loss, there is no cure, but hearing aids and other listening devices help treat the problem and improve quality of life.

Medical treatment

Medical treatment, including medications and surgery, 对于许多类型的听力问题都是推荐的吗, particularly conductive hearing loss. However, even if medical treatment is not necessary for your type of hearing loss, we highly recommend a visit to an audiologist for both a definite diagnosis of the type of hearing loss and treatment advice.

Some of the most common causes of conductive hearing loss are fluid in the middle ear, with or without infection, and earwax blocking the ear canal. In cases where there is a bacterial infection of the middle ear, antibiotics are often used. Although these conditions often can be diagnosed and treated by a primary care doctor, 持续的问题可能需要耳科专家的照顾. Conductive hearing loss also may be caused by a problem with the bones of the middle ear, which, in many cases, can be treated with surgery.

Hearing aids

如果被诊断为听力损失，无法进行医学治疗, a doctor will recommend a hearing aid evaluation and consultation with an audiologist. This consultation appointment will help determine which hearing aids or other assistive listening devices would be most appropriate. Lifestyle, listening needs and hearing concerns are important in determining the appropriate hearing aids.

辅助听力、听力增强和警报装置

In some cases, hearing or alerting assistive devices may be recommended in addition to, or instead of, hearing aids. 助听器技术有两种形式:

• Signaling or test display devices. These are designed to convert sound or keystrokes into visual or vibratory stimulus, or into a written text.
• Assistive listening devices. These instruments are designed to enhance the sound that is received by picking up the sound closer to its source. This reduces the effects of distance, noise and reverberation and transmits sound directly to the ears or hearing aids.

There are a number of devices that can assist hearing in a variety of settings. These include:

• Large Area Listening Systems
• Television Listening Systems
• Conference Microphones
• Personal FM Systems
• Amplified Telephones

有关上述每种设备的详细信息，请参阅 Hearing Enhancement Devices.

Signaling and text display systems

People with hearing loss can benefit from signaling and substitution systems, 将声音或按键转换为另一种模式, such as text or flashing lights. These systems include:

• Signaling and Warning Systems
• Telephones
• TV Closed Captioning

使用数字手机和助听器

A common complaint of hearing aid users is the inability to use cell phones, particularly digital cell phones, with their hearing aids, 或者他们在尝试这样做时会受到干扰. Digital hearing aids are being continually updated to provide shielding from this interference. 手机技术也在发生变化. In fact, in 2003, the Federal Communications Commission (FCC) developed a report requiring a number of future actions by manufacturers and service providers to make digital wireless phones that are capable of being used effectively with hearing aids.

In the meantime, there are many strategies that will improve listening when using cell and land based telephones with hearing aids. For more information, please see Strategies for Using Your Cell Phone with Your Hearing Aids.

Cochlear implants

A cochlear implant is a small electronic device that can help improve the hearing of people with severe, irreversible hearing loss. 虽然人工耳蜗并不能恢复正常的听力, it can allow a person to hear and understand more speech than was possible with a hearing aid. The Cochlear Implant Center at UCSF Medical Center has been involved in the development and design of cochlear implant systems for over 30 years.

Aural rehabilitation and listening and auditory communication enhancement

Unfortunately, hearing aids will not correct hearing loss or restore hearing to normal levels. However, the use of hearing aids and assistive listening devices along with auditory training can help maximize hearing abilities. Training may consists of:

• Audiologic rehabilitation classes
• Learning good listening strategies
• 建立与周围人沟通的准则

In addition, UCSF Audiology researchers are leaders in the quest to develop home based therapies for enhancing listening ability.