later well we noticed poor performance and a hearing test at some point in our hair cells start to deteriorate across the entire frequency range of the coakley that's what we call a dead region where sound is no longer being encoded dog but god can china could get. the function of hair cells is to convert the mechanical waves they pick up into nerve signals. if only a patchwork of hair cells remain our hearing becomes limited. there are some 20000 hair cells in the inner ear. but only $3600.00 of them are responsible for converting and transmitting most of the signals received they're the ones doing the heavy lifting. but per system noise or noise that is too loud can damage the hair cells beyond repair this damage is often irreversible. once a hair cell loses its functionality it can't be reactivated.

3600 hair cells is a finite number. if they stop working our inner ear looses the ability to hear. this can happen as a result of acoustic trauma or of gradual hearing loss which affects a growing number of people. could restoring the sign absence between hair cells and nerve cells restore someone's sense of hearing. this is what professor charles mckenna researches at the university of southern california. i have a theory that hearing loss is associated with older people of their uncle their grandfather. speak up please i can't hear you there may be

a lack of realization that this is a process that can be get very young age and especially if you're being exposed to very loud sounds for example devices placed in your playing music that is too loud . and there's guys in damage and the damage accumulates over time. hearing loss is very gradual it isn't like you wake up the day after a big music concert where the music was extremely loud you say deaf. it is insidious it is taking place very slowly and in perceptively if you will it's a little bit like protecting yourself from the sun you know you have to wear sunscreen but if you don't wear it a particular day you don't get student cancer the next week it's something that's slow in insidious according to the world health organization over 450000000 people worldwide suffer disabling hearing loss they can no longer hear

a clock ticking the figure includes $34000000.00 children and young people a solution to the problem is urgent. charles mckenna and his colleagues are looking for a method to reverse hearing loss caused by non functioning hair sounds. almost all adults will experience age related hearing loss the older they get the harder it becomes to detect higher frequencies. young people on the other hand have no problem with that sound. but anyway it's a ring tone where you can hear it and i hear it so. you're reading but if. i was 10 or so. the. gradual loss of hearing often goes undiagnosed for some time

even though it affects a person's everyday life and their social life and. well i can think about for example my own father who passed the age of about 60 years started to have noticeable hearing loss he had to use a hearing aid. and. i was really struck by the way he began to feel isolated even within our own family because of difficulties in communication and he started to complain that people don't speak up or in a restaurant where people talking so loud it can talk to my mom i also saw the progression how it gets worse and worse the hearing ability declines and the impact therefore grows on on the person. it's easy to distinguish the effects of hearing loss in a noisy environment when we converse our brains filter speech out of the

surrounding sounds to understand speech the brain needs to detect the higher frequencies that set speech apart from other sounds for young people and people whose hearing is fully intact this is easy. but older people start to lose the ability to hear high pitched sounds and struggle to filter speech out of background noise. all they can hear is a muffled hum conversing becomes increasingly challenging they need people to speak up. children have no problems filtering speech out of a wall of sound. this is roughly how conversation sounds to someone with age related hearing.

and this is how it sounds to a child or teenager. who climbed down. on one of. those. young people hear a wider frequency range children in particular are good at filtering speech out of ambient noise. alarmed by the prospect of hearing loss to students in miami florida have decided to do what they could to prevent it i have been music my entire life i did choir and then i was the vocalist for the jazz band at my high school i i realized since i was young 14 that it could affect me at such a young age and i really had no idea and i was a little worried too as a musician. kelly call hain and ben manley were still at school when they joined

a nonprofit organization that raises awareness for hearing loss. in online videos aimed at young people kelly talks about ways they risk damaging their hearing after learning about. the issue about how widespread it is and how it's a global health topic it really changed my behavior i didn't necessarily limit how much i was involved in music and stuff like that i just changed my approach to it and i'm just much more cautious now about how you know how much exposure i'm getting. but few young people are likely to take similar precautions even when they know the risks i mean for a lot of people especially young people the appeal to a loud noise is just so it's so big that like it's so fun to put in your headphones or just blast at full volume it's so fun to put your speakers on in your room and

pull last a full volume or go to a party and stand right next to speakers and feel the bass in your chair feel the vibrations it's fun and that's why a lot of people do it. people start to realize the tradeoff of short term pleasure versus long term pleasure yeah if you have a lot of the short term pleasure of loud noises everywhere in your headphones and at parties and events then you're going to miss out on the long term pleasure of just even being able to hear in general later in life. loud music is one of the main causes of hearing loss. but that doesn't stop most of us from enjoying it. we just encourage people to be more cautious about how loud the sound is and take notice when it is too loud. we want people to grow up knowing that protecting their hearing is important we

want to be normal and and cool i have. ear plugs that fit right on my key jane and i bring those everywhere with me and if it's too loud i pop in and really people don't notice that they're in your ear unless they're actually looking for it these are great because they may filter out high frequency sound and allow you to still hear everything so have conversations with people and it just you can hear things better. hearing is the ability to perceive sounds but what it gives us goes far beyond that. this principle combined with his own experience gave the. dheeraj the idea for his business. about children are now dog dining allows people to rediscover their other senses in this setting the sense of hearing becomes something almost magical you know the guest spend a couple of hours talking to a stranger they can't see it creates an instant bond like our hearing allows us to

intimately connect with the people around us you went to a world of emotion of laughter and can picture what your environment and the people around you might look like but it's funny when people leave the restaurant and actually see each other then they greet each other as if for the 1st time even though they've just spent the last 2 hours chatting. with the guests are greeted by blind waiters who lead them into a dining area that is pitch black out. there they must rely on their hearing to orient themselves and communicate with the other diners most aggressive . as we film here we too can only rely on our ears and the power of our imaginations. if one. ever saw any sort of mess. so when the guests leave the restaurant they

notice a heightened sense of hearing smell and touch. it's as though taking away their ability to see rewired and enhance their other senses. this is the 1st time they can actually see what they ate. to at least not come out much i got the feeling that my other senses were more intense partly because the ambient noise was somehow different. when you enter a dark quest aren't the 1st thing you hear the other guests confessing that the start of speaking quietly then at the end when you leave everyone is speaking really loudly. the atmosphere is great your senses feel alternate you focus on the person you're speaking to much more i had never really thought about the importance of hearing. this experience gave us a whole new perspective so just very interesting that we noticed things we wouldn't normally notice the battle for the.

researchers in getting and hope the up to genetic code clearer implants will help people with hearing impairments distinguish a wider variety of sounds. hues algae proteins to render nerve cells light sensitive. kind hearts are. forbidden if you've lost your hair cells you still have the corresponding nerve cells. in for that's where we use a viral vector to position the light switch. along the nerve fibers and then the cell body. and then when the light from the coakley or implant hits it off it triggers the light switch and stimulates the nerves when it's just it's. ultimately

we bypassed the degraded hair cells and their sign up says and activate the nerve cell directly. detect i don't know if it's are. genetically reprogramming cells in the coakley is a bio chemical process that is still being clinically tested it's not ready for human trials the stall is. good. that's the great part is it works very well. we can see that the early days provide an improved resolution it in our kitchen called records lists are in experiments with rodents and we recently. showed that there was no difference between a hearing with a light and acoustic hearing in soft and medium sound ranges. it's the size. it's just as good which in the next few months we'll be able to quantify this advantage was in weeks. there.

at the getting an institute studies of monkeys are helping scientists refine and optimize optical cage one particular species are the closest proxy researchers have to the human brain when it comes to hearing and speech. right side. we are in vice the snuffing this is an exact line work with marmosets which are very small monkeys that way around 400 grams also there are about the same size as the new her 4 picked animals to experiment with and i feel that auditory research is because they operate with an unusually broad vocal repertoire in a social context and in short they communicate with sounds which is of course very interesting for auditory researchers and scientists. in one experiment with marmosets a monkey is led to believe that another is calling out the sounds are gradually

modified to resemble the quality of a coakley or implant so the researchers can determine at what point they become unintelligible. so this is what's interesting about this experiment is that the same vocalization sounds are usually used by both animals communicating for 3 or 4 in the wild animals can end up separated from the group when that happens when they're a bit far from the group say fortunes for food on another tree country vocalize with long distance contact calls so called the costs if you know them if you can hear them very clearly the call is answered with a b. call and this form of vocal interaction occurs when the monkeys can't see one. other computers will so i can take advantage of that and replace one of the monkeys with a computer simulated calls then i can modify the call to explore the effects of a cochlear implant with various channels. will the same vocalization still occur but will the monkey keep responding with the be called missed. with their special

communication skills marmosets could provide researchers with the key to a new form of hearing in humans venison so i think. we hope to demonstrate the viability of an obstacle cochlear implant that is to show that it can function significantly better than an electrical cochlear implants people food and this would be of its vast improvement for patients and we could then not only improve the auditorium freshens but also bring about a fundamental improvement of the overall hearing experience thought that such a challenging and very exciting prospect. but. it will take another few years of research and testing before the 1st patients can be fitted with optical coakley or implants. the researchers at the institute in getting in are trying a number of different approaches. one group is investigating ways to help

people here again without any technical ends. soon as you know this is a sensory cell in the in a uses a very unusual mechanism with very unusual molecules to transmit signals to the nerve cell for gives very different compared to the sign ups in the brain that we have a pretty good idea of which proteins are used to signal transmission can be in the in a way less familiar with the molecules that play a role in this but we know that one of them is otoh furlan a very large protein we know that if it's not then no signals are transmitted from the sensory cells to the near arms in previous studies we establish that low levels of oto phailin in the membrane are enough to cause deafness in a member. the researchers have identified a form of deafness related to a patient's physical state a sort of on off deafness. i didn't have there are patients who have more

or less normal hearing a normal body temperature is a might have a little trouble understanding speech but interestingly when they have a fever a temperature of 38 degrees or above they're almost completely deaf and when we looked into this and found that this oto furlan protein is so temperature sensitive that it a high temperature it completely disappears from the plasma membrane and. based on these findings researchers have developed an approach that allows them to fully restore hearing now my natal used in line of deaf mice who lacked the genes for otay ferland in other words they were otoh further in deficient with the help of 2 viruses we succeeded in reintroducing the gene that in codes it into the sensory cells as we were able to at least partially restore hearing in these mice the next step is to do the same with humans 1st we have to find she you know our approach

and improve the level of hearing we can restore schools but we hope to be able to offer gene therapy to people who have been related deafness on this but album to him much better than with an electrical or optical cochlear implant and. hearing compliments what we see it completes the world we experience. in that complex of our senses hearing is a dimension of its own. it gives us our spatial awareness. lets us feel distance and intensity. in evolutionary terms our hearing is attuned to the sounds of nature. we can detect even the slightest noises from far away. 6 animals can hear even better than humans

for humans the sounds of nature are associated primarily with rest and relaxation. and less with hunting and personal protection. for humans today other aspects of hearing play a more important drawl. charles mckenna's research aims to ensure people will continue to be able to hear well as they age despite damaging environmental influences. he's collaborating with harvard medical school in boston and researching the bone of the coakley and as a docking point for drugs that can cure hearing impairment. we had been working on the bone velcro concept in this really so way to create images

for diagnosis of diseases of the ball and and so we had created a imaging probe that the liver is a fluorescent imaging agent to ball. originally intended to identify bone damage in our studio perot's is the substance was shown to work here perfectly to the bone structure of the coakley. we tried and we saw the compounds can beautifully imaged the cochlea similar bone structure of the year that's where we began to think. this fast funny it can reach the structure why not give it a cargo a drug to carry into the structure so that that drug could work in the structure and the drugs already existing that have promise for curing diseases of the year that have a delivery problem you can't keep them in this cochlear structure and so the

idea of the bond is if you can get the drug into the interior of the cochlea it stays there and how to get it to stay there you encourage to the ball. until now the fluid exchange that takes place in the coakley meant that substances couldn't get here there and be effective. at harvard medical school in boston researchers are working on substances that should be able to reverse hearing impairment and hearing loss in the coakley. we. knew about such a drug and they said you know is there a way to take your bones all crow and combine it with this drug and so we thought about it and we said yes we can do it. the challenge for the bio chemists lies in anchoring the substances to restore hearing in the bone without causing complications i think what we're aiming

for is a drug to a complete delivered to the year to the inner ear and in the ideal case a single dose would be effective but it might be several of those this is something we don't know yet the dosage that dosing regimen and so forth. lengthy testing and approval process is mean it will be years before a drug can be marketed. purslane that's really i'm very confident. but i'm also a realist as a scientist to objective you know the statistics on the other hand. you you have to feel confident that you can beat these statistics otherwise why would you attempt this endeavor in the 1st place. los angeles alone is home to millions of

people who would benefit from such a medicine. and there's no question given the obvious need we're talking about as substantial percentage of people around the world. world's population is what 7 or 8000000000 people a significant percentage of those persons have hearing disability of various degrees and so naturally. they have hope that someone perhaps us perhaps another group will come up with a drug that can help them. our hearing has to be able to withstand the demands of everyday life it helps us orient ourselves and sometimes it lets us shut out the world. cheering is one way to maintain social contact it's a source of pleasure. most people hardly notice how their hearing slowly

changes how their ability to hear and therefore communicate with others fades over time. to some extent our sense of sight can compensate for hearing loss. but nothing can replace the wonder of hearing. the world is moving in the right direction the world is moving towards caring about hearing much more and again it hasn't even been a problem for the long and there are so many different problems that have existed since like since the dawn of man sadly all the like heart problems and just like all these general health conditions and sight but it's a loud noises really like like continuous so exposed to loud noises really only blew up in the sense like the industrial revolution so it's only been in the last

like let's say 150 years that people start to be exposed like on a daily basis to noises that will really damage your hearing. if it is astounding i'm amazed by how much information exchange through the language through here and i'm mostly fascinated by how closely hearing is linked to emotions that is when i hear music the tiny whelan's like very much just thinking about it gives me goosebumps all brings tears to my eyes no other sense can do that not even the sense of sight which also allows us to absorb information what i see doesn't touch me as deeply as what i hear it is. just that in constant touch. and these new contacts tense which means in this all day long we are transmitting information at crazy speeds from contact points between the sensory cells and the auditory nerve is enough so that as a thing the sign ups is released messenger substances all day long and the whole

thing happens with a temporal precision of less than a millisecond i think and that this is one of them is a soup of wood and all this has been developed from proteins and ions on the like this it's fascinating that is took sage and something with us and. must proceed on some systems new kind of won't. buy were to lose my hearing i would be very depressed because deep. it would probably be the end of my social life will be the full movie you know if i ever lost my hearing with this i would probably wonder if life was still worth living if you do call the news or boast and lucky some continuity will supposedly come. you know everything begins with the discovery. to have made this kind of discovery together with my colleagues. is enormously satisfying. this is really what inspires our work because we are thinking always about

can the work we are doing ultimately help some of these people. became conditions yet is stifling kurdistan's capital is suffocating smog the reason outdated cooling. residents and activists are fighting back against the air pollution but within the government their demands are falling on deaf ears for the. global 3000. and 30 minutes on d w. small acts can inspire the changes for the people

making small going for a fantastic night. join them as they set out to save the environment learn from one another and work together for a better future. many thoughts to you all for tuning in for good. night. the minutes on d w. what is different on the islands of the sound. you hear women are in charge. the archipelago has a matriarchal system for centuries and. the rare form of society.

to live differently. what do they do with their power. and how sustainable is this culture. leans over rango starts more change on t.w. . this is day they'll begin news and they use are out top stories one of 3 men accused of murdering multis journalist duff in a car wanna go has been sentenced to 15 years in jail it came off to he unexpectedly china plea to guilty and admitted to all charges against him kyra want to go.