Gare aux effets des baladeurs MP3 sur l'audition

Les baladeurs MP3 d'aujourd'hui ont envoyé le Walkman au rayon des antiquités: il est maintenant possible d'écouter de la musique de bonne qualité pendant des heures et à des volumes de son élevés. Souvent trop élevés. 

Et les spécialistes sont de plus en plus inquiets des conséquences néfastes pour l'audition des adolescents avec l'apparition de plus en plus précoce de baisse sensible de l'audition, que certains appellent même une «épidémie de troubles auditifs».

Un adolescent sur quatre est à risque d'une perte d'audition résultant directement de ses habitudes d'écoute avec son baladeur, affirme ainsi le Pr Chava Muchnik, de la Tel Aviv University au terme de son étude, publiée dans l'International Journal of Audiology. 

Près de 289 adolescents, entre 13 et 17 ans, ont participé à l'étude. Ils ont été interrogés sur leurs habitudes d'écoute avec leur iPod ou autre baladeur MP3. Et en particulier sur le niveau sonore et la durée d'utilisation. Dans un deuxième temps, le volume du son des baladeurs a été mesuré chez 74 adolescents dans un environnement calme puis dans un environnement bruyant. Les volumes mesurés ont servi à établir les risques potentiels pour l'audition des adolescents.

Près de 80 % des adolescents participants à l'étude utilisaient leur baladeur très régulièrement, 21 % d'entre eux l'écoutant de 1 à 4 heures, et 8 % s'en servant plus de 4 heures consécutivement.

«Dans 10 ou 20 ans, estime le Pr Muchnik, il sera trop tard et on verra que toute une jeune génération souffre de surdités partielles beaucoup plus tôt qu'attendu en fonction du vieillissement». Elle recommande ainsi que tous les pays adoptent, pour commencer, les normes européennes qui limitent à 100 décibels le volume maximal des iPod et des baladeurs MP3, dont certains, non «bridés», peuvent atteindre près de 130 décibels. Mais 100 dB, cela équivaut déjà au niveau acoustique d'une boîte de nuit. Et l'on sait qu'un risque pour l'oreille est déjà avéré à partir de 80 dB. Les spécialistes recommandent que des campagnes de prévention soient menées pour sensibiliser les enfants et les parents aux dangers de ces décibels.

Info sur Le Figaro SANTÉ

72% of Teenagers Experienced Reduced Hearing Ability After Attending Concert

M. Jennifer Derebery, MD, House Clinic physician, along with the House Research Institute tested teens’ hearing before and after a concert.

The hearing loss that may be experienced after a pop rock concert is not generally believed to be permanent. It is called a temporary threshold shift and usually disappears within 16-48 hours, after which a person’s hearing returns to previous levels. “Teenagers need to understand a single exposure to loud noise either from a concert or personal listening device can lead to hearing loss,” said M. Jennifer Derebery, MD, lead author and physician at the House Clinic. “With multiple exposures to noise over 85 decibels, the tiny hair cells may stop functioning and the hearing loss may be permanent.”

In the study, twenty-nine teenagers were given free tickets to a rock concert. To ensure a similar level of noise exposure for the teens, there were two blocks of seats within close range of each other. The seats were located in front of the stage at the far end of the venue approximately 15-18 rows up from the floor. The importance of using hearing protection was explained to the teenagers. Researchers then offered hearing protection to the subjects and encouraged them to use the foam ear plugs. However, only three teenagers chose to do so. Three adult researchers sat with the teenagers. Using a calibrated sound pressure meter, 1,645 measurements of sound decibel (dBA) levels were recorded during the 26 songs played during the three hour concert. The sound levels ranged from 82-110 dBA, with an average of 98.5 dBA. The mean level was greater than 100 dBA for 10 of the 26 songs.

Following the concert, the majority of the study participants also were found to have a significant reduction in the Distortion Product Otoacoustic Emissions (OAE) test. This test checks the function of the tiny outer hair cells in the inner ear that are believed to be the most vulnerable to damage from prolonged noise exposure, and are crucial to normal hearing, the ability to hear soft (or low level sounds), and the ability to understand speech, especially in noisy environments. With exposure to loud noise, the outer hair cells show a reduction in their ability to function, which may later recover. However, it is known that with repeated exposure to loud noise, the tiny hair cells may become permanently damaged. Recent animal research suggests that a single exposure to loud noise may result in permanent damage to the hearing nerve connections themselves that are necessary to hear sound.

Following the concert, 53.6 percent of the teens said they did not think they were hearing as well after the concert. Twenty-five percent reported they were experiencing tinnitus or ringing in their ears, which they did not have before the concert.

In the most recent government survey on health in the United States National Health and Nutrition Examination Survey (NHANES) 2005-2006, 20% of adolescents were found to have at least slight hearing loss, a 31% increase from a similar survey done from 1988-1994.

“It also means we definitely need to be doing more to ensure the sound levels at concerts are not so loud as to cause hearing loss and neurological damage in teenagers, as well as adults,” said Derebery. “Only 3 of our 29 teens chose to use ear protection, even when it was given to them and they were encouraged to do so. We have to assume this is typical behavior for most teen listeners, so we have the responsibility to get the sound levels down to safer levels.”

Researchers recommend teenagers and young adults take an active role in protecting their hearing by utilizing a variety of sound meter ‘apps’ available for smart phones. The sound meters will give a rough estimate of the noise level allowing someone to take the necessary steps to protect their hearing such as wearing ear plugs at a concert. In addition, Derebery and the study co-authors would like to see concert promoters and the musicians themselves take steps to lower sound levels as well as encourage young concert goers to use hearing protection.

Info accessed at Science Daily

5 ways to listen better - Julian Treasure

In our louder and louder world, says sound expert Julian Treasure, “We are losing our listening.” In this short, fascinating talk, Treasure shares five ways to re-tune your ears for conscious listening — to other people and the world around you.

(Recorded at TEDGlobal 2011, July 2011, in Edinburgh, Scotland. Duration: 7:50.)

From TED

Evelyn Glennie shows how to listen

Evelyn Glennie is a scottish percussionist and composer. She lost nearly all of her hearing by age 12. Rather than isolating her, it has given her a unique connection to her music.

In this soaring demonstration, deaf percussionist Evelyn Glennie illustrates how listening to music involves much more than simply letting sound waves hit your eardrums. She leads the audience through an exploration of music not as notes on a page, but as an expression of the human experience. Playing with sensitivity and nuance informed by a soul-deep understanding of and connection to music, she talks about a music that is more than sound waves perceived by the human ear. She illustrates a richer picture that begins with listening to yourself, and includes emotion and intent as well as the complex role of physical spaces — instrument, concert hall and even the bones and body cavities of musician and listener alike.

Recorded February 2003 in Monterey, California. Duration: 32:20
From TED

Another great testimony illustrating that hearing loss doesn't imply the loss of musicality! :)

Sound level limits for personal music players and mobile phones

CENELEC Technical Committee 108X on ‘Safety of electronic equipment within the fields of Audio/video, Information Technology and Communication Technology’ was tasked to take the execution of the mandate on board. The work was performed by a dedicated working group with representatives and experts from market surveillance authorities, consumer interest organisations, research institutes, certification bodies and manufacturers.

The exercise resulted in the issuing of 2 amendments to already existing standards for ‘Safety of audio, video and similar electronic apparatus’ and 'Safety of information technology equipment', which passed a formal vote by the National Standardisation Committees at the end of 2010.

The approach adopted in the standard is based on a sound level limit of 85 dBA. This is a sound level that is considered to be safe under all reasonable foreseeable conditions of use. There is the possibility however for the user to choose to override the limit so that the sound level can be increased up to a maximum of 100 dBA. In this case the user has to be provided with warnings about the risks which are repeated following each 20 hours of listening time.

After publication of the amendments in early 2011, a transition period of 24 months will follow, during which the standard will be implemented at national level by the publication of national standards. By the end of the transition period, industry should have started to apply the standard to their products.

In the meantime, the working group is expected to continue with the next step of the mandated work, which is the development of "smart" methods of providing protection against excessive sound pressure levels from personal music players based on the measurement of sound dose.

Brussels, Belgium, 2011-02-09

More info here.

Read the previous article.

Para quem gosta de ouvir música ...

... e pretende continuar a ouvir com qualidade até pelo menos aos 100 anos...
... é melhor pensar duas vezes no volume do leitor de música!

Dêem uma olhadela neste filme.

Acedido em Make Love not Hearing Loss

Festivais, ruído e CHECK-IN

Como frequentadora assídua de festivais, conheço o CHECK-IN há coisa de quatro anos. Os responsáveis pelo CHECK-IN autodefinem-se como um grupo de pessoas que procuram contribuir para uma melhor Gestão de Prazeres e Riscos associados ao consumo de substâncias psicoactivas e à sexualidade. O CHECK-IN intervém em contextos festivos de qualquer tipo, desde festas de música electrónica, festivais de verão, festas académicas etc.

Fiquei sinceramente e positivamente fascinada quando, no Boom 2010, ocorrido no passado mês de Agosto, me deparei com a divulgação de Informações relativas a um novo tema: o ruído! Desconhecia esta vertente de divulgação do CHECK-IN e fiquei motivada para a causa deste blogue, pois considero ser um dos pontos mais importantes a prevenir no seio de eventos festivos como o Boom. Em contrário, e considerando que apenas uma pequena parcela da população está consciencializada para os perigos de ouvir música em alto volume, teremos tendência a sofrer uma degradação gradual do órgão auditivo, e consequentemente, da capacidade de desfrutar o maravilhoso mundo da música, os concertos mais inquietantes e os festivais mais interessantes...


Passo a citar alguma da informação disponíibilizada pelo CHECK-IN:

OUVE BEM…

TÁS A OUVIR!?...

Para quem aprecia a música é muito importante preservar a audição em boas condições para continuar a curtir o som com a mesma qualidade.

Se ouvir música é acima de tudo um prazer, quando o fazemos repetidamente com volumes demasiado elevados passa a apresentar também alguns riscos.

Se frequentemente expões os teus ouvidos a um volume demasiado elevado, o teu sistema auditivo está sujeito a um desgaste demasiado prematuro. Os músicos, dj’s e os frequentadores assíduos de festas estão, por isso, mais propensos à perda de acuidade auditiva.

O risco de perda auditiva pode aumentar consoante:

O volume da música;

A proximidade das colunas;

O tempo de permanência no dancefloor;

Eventuais problemas auditivos anteriores.

Se tens alguns dos seguintes sintomas não hesites em consultar o médico!

Zumbido constante nos ouvidos;

Sensibilidade a ruídos altos;

Dificuldade em ouvir os outros quando existe barulho de fundo;

Sensação de que os outros comem as palavras ou falam demasiado rápido;

Tens sempre que lhes pedir para se repetirem;

Tens sempre que aumentar o volume da TV;

Ouves o telefone melhor com um ouvido que com o outro.

Para evitar chegar ao ponto de apresentar os sintomas acima descritos há que ter certos cuidados ao ouvir música e noutras situações.

Não te esqueças...

Os níveis de som nas discotecas podem chegar aos 120 dB e a margem de risco para os teus ouvidos é de 90dB. 120dB é já considerada margem de dor!

Fica pelo menos a 3 metros das colunas. Dançar junto das colunas aumenta os riscos! Faz pausas de 10 minutos a cada 45 minutos e de 30 minutos a cada 2 horas, em locais onde o som é mais baixo.

O algodão ou bocadinhos de tecido não protegem. Usa tampões! Assim, estás protegid@ mas não deixas de curtir o som.

O cansaço, a desidratação e o sobreaquecimento também aumentam os riscos. Assim já sabes mantém-te hidratado e faz pausas!

Se ouves música com head phones internos evita fazê-lo muito tempo seguido, faz pausas e não abuses do volume. Devido à proximidade com o ouvido, osphones internos causam grande pressão acústica pelo que os externos são preferíveis.

Se trabalhas com material sonoro ou com máquinas ruidosas usa protecção auricular. Além da música outras fontes de perigo excessivo podem ser as viaturas, maquinaria, televisão, jogos, etc.

Fiquem atentos e baixem o volume!

Para mais informações, consultar http://check-in.apdes.net/quediz/img/checkinews_06.pdf

Força CHECK-IN, continuem o bom trabalho que têm desenvolvido! Os festivaleiros precisam de vocês :)

Imagem acedida em:

http://preditor.mio.co.za/assets/articles/images/resized/12109_resized_blackcoffee300.png

''A qualidade da música é inversamente proporcional à intensidade do som"

Isaac Rocha