I can't hear the "pee" of home appliances-why is it still unsolved?

September 18, 18:48

Today's life, "ping-pong" from the front door, "pee-pee" from the kitchen, "pee-pee" from the thermometer ... Electronic sounds are heard here and there.

However, there are some sounds that are difficult to hear for the elderly and sick people who have become deaf as they get older, and posting such troubles is gaining sympathy on the Internet.

Why can't we solve this problem that seems new but has been around for a long time?


(Network news department reporter Naoya Saito, Hokuto Takasugi,


 SNS research Nozomi Nagano, Go Lee)

"I can't hear the sound of home appliances"

This month, such a message posted on SNS became a hot topic.

"Mother becomes older, ish" Phi, Phi "Ttoi' was high-pitched tone is difficult to hear, even leave it is Yara time extension Announcement sound of the warning sound and the fan heater of left open the refrigerator, do not notice at all.


Now consumer electronics I want manufacturers to develop products with an interest in sounds that are hard to hear as they get older. "

There were more than 30,000 retweets, and there were a lot of sympathetic voices from people with similar experiences.

"My mother also said was not hear the sound signaling the end of the washing machine,"



"sandwich much unaware of the Phi sound also of the electronic thermometer of the parents out.


Looking out at Yamakan"



"Actually microwave oven I can't hear the chin, the sound of boiling water, the sound of burning, or the sound of the washing machine finishing, so it's quite difficult to check every time. "



" When the children are at home I'll tell you, but I'm worried about the future.


Sometimes I can't even hear the interphone, so I'm very sorry for the redelivery. "

I was able to talk to a man in his 50s who lives in Gifu prefecture who made the original post.


Living with parents in their 70s, a 77-year-old mother has had difficulty hearing the high-pitched sounds from home appliances, especially for the past two years.



When the sound of forgetting to close the refrigerator was heard, the father could hear it, and sometimes he would say, "Can you hear it ringing?", And I saw my mother messing around.

However, this time, he said, "I'm going to ring, I'll close it properly," and he had the same strong tone as his father, and he was disgusted by himself, which was the reason for the posting.

A man in his 50s who made the original post


"I tweeted from my feelings of self-loathing and wondering if I could do something about it. I'm glad to hear many requests for improvement."

Why are you deaf?

In general, the older you get, the harder you hear, but there is a graph that shows the tendency of what kind of sounds are hard to hear according to age and gender.

ISO = data compiled by the International Organization for Standardization.



The influence comes out from about 40s.

It tends to be difficult to hear from high frequency sounds, that is, "high frequencies".

And we can see that men tend to be more affected than women.



What is the cause of deafness?



We asked Masato Fujioka, a full-time lecturer at Keio University School of Medicine (Otorhinolaryngology).

"The detailed cause has not yet been clarified, but it is said that the" hair cells "that convert sound into electrical signals and transmit them to nerves are damaged with age. And the cells that hear higher sounds are damaged. It ’s considered easy. ”

It seems that cells may be damaged not only by age but also by listening to loud noises and habits such as smoking.



On top of that, he points out that there are individual differences in how they are heard.

Keio University School of Medicine (Otorhinolaryngology) Masato Fujioka Full-time Lecturer


"Symptoms progress differently, and patients with Meniere's disease may not hear low-pitched sounds. The ears are" consumables "where cells are easily damaged. There is also an aspect like "I want young people to take good care of it."

Even young people with hearing loss

Some young people have hearing loss.



A woman in her thirties in Hyogo Prefecture, who had seen and commented on her mother who couldn't hear the sound of the refrigerator earlier, was diagnosed with "conducting hearing loss" when she was young and had a weak bone-transmitting function.



When I go out, I wear hearing aids in both ears, but I still can't hear the high-pitched sound of the thermometer, and when I measure the temperature at the hospital, ask the people around me, "Please tell me if you hear a sound." It seems that it is.

A woman in her thirties in Hyogo Prefecture


"It was a daily routine for me to not hear the treble" pee ", so I was shocked by that post. I can't see the difficulty of hearing, so I can say it. I thought it was important. "

According to the "All Japan Federation of Hearing Impaired and Premature Hearing Persons Associations" that supports the hearing impaired, many consultations regarding the sound of home appliances were received, including refrigerators, thermometers, automatic water heaters in the bathroom, and intercoms at the entrance. Some people say that they can't hear the sound or even the ringing sound of the phone.

I can't tell which sound it is

In addition, some people say, "Even if you can hear the sound, you cannot tell what the sound is."



People with visual impairments sometimes rely on sound to live, but according to Mr. Tadashi Osaka, general manager of the Japan Association of Visually Impaired People, similar sounds are used in multiple home appliances, and which product Some people say that it is difficult to distinguish whether it is a sound or not.



For this reason, he has requested consideration from organizations that develop welfare products and equipment.

Tadashi Osaka, General Manager, Japan Association for the Visually Impaired


"Sound is often relied on by people who are blind. Many people live independently, so it is easy for anyone to hear and it makes sense. I want the sound to be easy to understand. "

Measures were taken

I feel that there are many requests for the sound of home appliances, but what are the countermeasures?



We asked Professor Kenji Kurakata of Waseda University, who specializes in ergonomics and psychoacoustics.

Professor Kenji Kurakata of Waseda University


"The problem that it is difficult for the elderly to hear the sound of home appliances has been pointed out for more than 30 years, and countermeasures have been discussed."

According to Professor Kurakata, in the early 1990s, home appliances became more high-tech and more sophisticated, and small electronic devices became the mainstream instead of bells and other parts that make sounds.



Along with this, the manufacturer was told that elderly users could not hear the sound.



Analog sounds such as bells produce sounds with a frequency range from bass to treble, but electronic sounds produce only specific frequencies, so if they are set to high frequencies, they will be almost inaudible to some people.



For this reason, industry groups made by major home appliance manufacturers and others have repeatedly discussed, and in 2002, JIS = Japanese Industrial Standards (currently Japanese Industrial Standards) was set as the standard for elderly-friendly products. Means that "do not use high-pitched sounds above 2500 hertz" and "change the sound pattern according to the type of notification" are stipulated.



Since then, industry groups have compiled product guidelines for the elderly and people with disabilities.



Products that are actually considered are on sale.

Terumo, a major medical equipment company, sells a thermometer that plays the nursery rhyme "Mary Had a Little Lamb" when the temperature is measured.



According to the person in charge, this song has a wide range of pitches, so it is easy for many people to hear.



Another manufacturer also sells thermometers that notify you with light or vibration.



The major electronics manufacturer "Sharp" has developed a product that blinks not only the sound but also the lamp inside when the refrigerator is forgotten to be closed, and some refrigerators that can change the frequency of the sound are also sold.

Why are so many people still in trouble?

Still, why are so many people in trouble?



Professor Kurakata of Waseda University first presupposes that


▼ the sound from home appliances is heard very differently depending on the place where it is placed and the surrounding environment,


▼ there are individual differences in how it is heard, and JIS and industry guidelines are used. It points out that it is difficult for everyone to be satisfied even if they meet.



On top of that,


▼ JIS and guidelines are just guidelines, and compliance is not obligatory, and


▼ It costs money to devise and develop products, but it does not necessarily lead to sales.

Professor Kenji Kurakata of Waseda University


"I think the background is that the aging of the population has progressed significantly in recent decades. Furthermore, the manufacturers of so-called white goods have diversified, and JIS and overseas manufacturers have manufactured JIS and overseas manufacturers. I think products that do not meet the guidelines are also widespread. "

I also asked the person in charge of a major home appliance maker.

A major manufacturer


"If you lower the sound, the volume will be low for the listener and it will be difficult to hear. There are also technical issues like this."



Another major manufacturer


"User's voice is used as a reference for product development, One or two people point out the sound of the refrigerator a year. It's not a big move to move the development site. "

To make it easy for everyone to use

In this era, the aging of the population is advancing, and the realization of diversity in which diverse people can play an active role is required.



What should we do to ensure that each person can live with peace of mind?



Experts point out that it is important to properly convey the user's voice to the manufacturer.

Professor Kenji Kurakata, Waseda University


"Even in the 1990s, when electronic sounds began to be used, manufacturers didn't know much about the fact that there were people who couldn't hear them, and the countermeasures were started in response to user suggestions. If you are a professor, please send that voice to the manufacturer. I think that each voice that you want to improve will lead to the realization of a universal design that is easy for the elderly, sick people, and people with disabilities to use. "

September 21st is Respect for the Aged Day.



Instead of having to give up something and put up with it, I want to create a society where the elderly can feel "I'm glad I lived a long time."