I'd like to start with a short demonstration（展示）. Now, I can't see many of you, but I'd like you to take your two fingers and put them lightly against the pointy bits in front of your ears. Now, I'd like you to push until your ears are completely plugged（塞）, and keep them plugged. What you're experiencing right now is mild hearing（ 听力） loss. Okay（好）, you can let go. What you're experienced just now is mild temporary（暂时的） hearing（ 听力） loss.

  In my audiology practice, I routinely（例行公事地） tested new patients with hearing loss twice as bad as you just experienced. Hearing loss is common for many of us. It's not a matter of if, but when we will lose some of our hearing. About half of us will acquire（获得） it by age 75, two-thirds of us when we reach our mid-80s. It's on the increase in children, and baby boomers（生育高峰中出生的人） are experiencing more hearing（ 听力） loss than those of past generations. If hearing loss runs in the family, there's a good chance you'll get it too.

  You've got to choose your parents wisely. But kidding aside（在旁边）, besides（而且prep除…之外） affecting quality of life, it can have serious repercussions such as depression（沮丧）, social isolation（隔绝）, contribute（捐献） to cognitive（认知的） decline, and even increase the risk of falls in older adults. Hearing loss is much more than a loss of volume（卷）, the kind of hearing loss that you just experienced. Pitches（程度） are heard unequally. My father could stand right under a smoke alarm, not hear a thing, but he had no trouble hearing the garbage truck rumble（ 发出低沉的隆隆声） down the street from inside the house. Hearing loss due to aging and noise exposure（暴露） changes how we understand speech.

  And it causes words that sound similar, like zip and sip（小口地喝）, wake and lake, mad and dead and bad to sound the same, especially when there's background of noise. And as unintuitive as it may be, loud sounds can become unbearable, loud, distortingly loud. Hearing loss is a complex problem. Perhaps you know people who, even wearing hearing aids（帮助）, still have to have the TV volume up, always watch TV with subtitles（副标题）, frequently ask everybody to repeat that. Would you please repeat that? Aren't hearing aids supposed to solve these problems?

  When I began helping people with hearing loss over 44 years ago, I expected that hearing aids would be like eyeglasses, and that wearing them would make（使） everything sound crystal（结晶） clear. If that were only true, I have personally witnessed（目击） over four decades of hearing aid（帮助） developments, advancements（进步）, from analog to digital devices, devices that can be remotely programmed, that include fitness tracking, and feedback（[无]回授） and noise reduction（减少） using artificial（人工的） intelligence, they still don't work（使工作） the way we hoped they would. And how can they? Hearing aids can't make hearing normal, they're good at making sound louder, but they can't always make sound（健全的） the speech clearer（清晰的）, especially when the inner（内部的） ear and the hearing（ 听力） nerve（神经） are affected. And hearing aid microphones（扩音器） have a limited（有限的） effective range of about four or five arms lengths. And hearing the world through these tiny hearing aid microphones reduces our exquisite（优美的） three-dimensional（空间的） hearing（ 听力） ability down to one dimension.

  Consequently（因此）, hearing aids（帮助） cannot improve the clarity（清楚） of the sounds we want to hear relative to the sounds we don't want to hear beyond that critical microphone（扩音器） distance, something that normal hearing ears accomplish（完成） effortlessly（毫不费力地）. Of course, hearing aids are needed to make sound audible（听得见的）, but for many they are not a complete solution, especially when you consider that hearing aids, at best, even the most advanced hearing aids, can only restore（恢复） about half of the hearing（ 听力） loss sensitivity（ 敏感）. Well, what about the other half? What about those microphone distance limitations（限制）? Better hearing is possible, and let's talk about some tools and some strategies that can make that happen. We're all familiar with these little wireless（ 无线的） earbuds that allow people to listen to music and make（使） phone calls whenever they're on the go.

  Did you know many modern hearing aids can do that also? Hearing aids can be paired via（经过） Bluetooth technology and an app on a smartphone to make（使） hands-free phone calling possible, as well as the streaming of podcasts and audiobooks and those Google Maps navigation（航行） directions right into hearing（ 听力） aids（帮助）.