As a part-time college lecturer, I know how hard it is to teach well, given my limited time and experience. Over the past few years, I鈥檝e had to double my effort in reading and writing to meet students鈥� increasing expectations for better thinking skills.

But my challenge is nothing compared with that endured by a 51-year-old teacher, who has devoted herself to deaf education for more than 30 years.

Since 1991, Liu Lingli, a teacher at a special education school in Hengyang City, Hunan Province, has taught only about 100 students. She has made far more efforts than me, though I鈥檝e taught more than 100 students in just five years. On most working days, sometimes even in her spare time, she has to toil round the clock, not just as a teacher, but as a caregiver, a mother-like figure indeed.

In 1991, Liu graduated from a special education college in Nanjing City, Jiangsu Province, at the age of 18, and then returned to her hometown as an instructor for deaf children.

She already began working like a mother at such a young age. Once, a little girl student, suffering from a slower mental development as well as hearing loss, went to the toilet and was later found to have smeared herself with the dirty stuff. Without hesitation, Liu darted toward where the girl was found, enfolded her in her arms and helped clean her body.

Similar stories abound. In the past 30 years or so, Liu have trudged through many harrowing paths to offer at-home lessons to some students who could not make it to the school. She accompanied a boy student to hospital for an emergency treatment at night. She donated her academic rewards to the school to help poor students with their studies. At one point, she even decided to postpone her plan to have a child so that she could focus on teaching.

Yet all these were not the toughest part of her career. The hardest time came in 2005, when her newborn baby was diagnosed with innate hearing loss. Her husband, refusing to face the reality, divorced her, leaving Liu to juggle alone between working with her deaf students and raising a deaf boy.

鈥淚t was a big blow to me, and I felt as if heaven had fallen,鈥� Liu recalled in tears in an interview with China Central Television. 鈥淒octors told me there was no hope of making my son speak, but I did not give up.鈥�

A 鈥榯ongue exercise鈥�

She knew that early intervention may help a child hard of hearing regain his or her speaking power, but at first she didn鈥檛 know how. Day and night, she browsed medical literature, while trying her best to explore and experiment with a unique 鈥渢ongue exercise鈥� to treat her son, who was about seven months old when doctors declared he had an 鈥渋rreparable鈥� hearing impairment.

Such a 鈥渢ongue exercise鈥� involves intensive movements of one鈥檚 tongue and other oral muscles so that one can 鈥渇eel and find鈥� the correct mouth shape for the pronunciation of a certain word. The mouth could feel extremely sore after such intensive exercises.

Liu鈥檚 relentless efforts paid off. Her son began to speak when he was 1 year old. Now, he has been enrolled in a renowned college, like any other normal student.

鈥淢om was strong-minded. I love her,鈥� the son said tearfully in the interview.

In 2008, Liu鈥檚 school began providing preschool education for little kids with hearing loss. Because of her experience in treating her son in the previous three years, she was appointed head teacher of such classes.

Don鈥檛 mistake Liu鈥檚 unique 鈥渢ongue exercise鈥� for a panacea. A child suffering from hearing loss may be able to move his or her tongue and other oral muscles freely, but they often have a hard time telling 鈥渉鈥� (an aspirated consonant) from 鈥渆鈥� (a vowel).

In that case, Liu would put a student鈥檚 hand before her mouth to let him or her feel the difference of breath in uttering the two letters. To help a boy student feel the position of the tongue in pronouncing gege, Chinese for 鈥渆lder brother,鈥� she even put his finger into her mouth to feel how the tongue touched the palate.

Of all the students Liu has taught since 1991, especially since 2005 when preschool education for kids hard of hearing began, quite a few have regained their speaking power, although their pronunciation may not always be standard.

Generally speaking, a baby should undergo checks of his or her hearing ability as early as possible, because the sooner one is diagnosed with hearing loss, the better. Certainly there are exceptions.

Liu Hanxiang, now a professional dancer, came to Liu Lingli鈥檚 class when she was already 8 years old, her vocal chord having become too rigid. Still, Liu succeeded in helping the girl speak, by teaching her one word per day.

A couple of years ago, Liu Hanxiang sent video greetings to her teacher, who was attending a CCTV ceremony for those selected as model Party members. As the girl expressed her gratitude in not very standard pronunciation, aided by sign language, many members in the audience were in tears.

A 鈥榯ouching鈥� story

In China, more than 20 million people suffer from hearing loss. In some cases, deaf students also find it hard to speak as they can鈥檛 hear the sound of a word. Many of them can only learn to communicate with sign language 鈥� talking with their hands in a world of silence.

Theoretically, a deaf child can learn to talk if he or she is diagnosed at an early stage and then gets timely treatment. But like many other things, it鈥檚 easier said than done. Without a devoted and capable teacher, a deaf child may lose a golden chance to walk out of a world of dead silence.

During this year鈥檚 National People鈥檚 Congress, which concluded on Monday, Liu, a NPC deputy, called for enhanced government support for special education for those hard of hearing. She also suggested hearing aids and cochlear implants be covered by the country鈥檚 medical insurance.

Liu鈥檚 story, popularized by a recent series of news reports, shows how a passionate teacher has persisted in achieving 鈥渁n impossible mission鈥� 鈥� helping children with hearing loss regain their speaking power.

The World Health Organization published a report last month, saying that more than 5 percent of the world鈥檚 population, or 430 million people, requires rehabilitation to address their disabling hearing loss, including 34 million children.

鈥淚t is estimated that by 2050, over 700 million people, or one in every 10 people, will have disabling hearing loss,鈥� said the report.

When it comes to interventional measures, WHO鈥檚 suggestions include speech reading and the use of hearing technologies such as hearing aids, cochlear implants and middle ear implants.

In a way, Liu鈥檚 鈥渢ongue exercise鈥� has enriched the concept of speech reading, thereby enabling more hard-of-hearing children across the world to get effective treatment at an early age.

According to the Centers for Disease Control and Prevention of the United States, 鈥渟peech reading (or lip reading) is a building block that helps a child with hearing loss understand speech. The child watches the movements of a speaker鈥檚 mouth and face, and understands what the speaker is saying.鈥�

The CDC further explains that about 40 percent of the sounds in the English language can be seen on the lips of a speaker but some words can鈥檛 be read. For example, 鈥渂op,鈥� 鈥渕op鈥� and 鈥減op鈥� look alike when spoken.

Similar confusion occurs in Chinese contexts as well. For example, 鈥渕ama鈥� (mom) and 鈥渂aba鈥� (dad) sound different to a normal listener, but in uttering the two words, one鈥檚 mouth looks the same to someone hard of hearing.

That鈥檚 where Liu鈥檚 鈥渢ongue exercise鈥� comes in. When 鈥渞eading鈥� fails, 鈥渇inger touching鈥� helps one with hearing loss to figure out how to pronounce a word.

It鈥檚 a 鈥渢ouching鈥� story.