sábado, 28 de septiembre de 2013

Hiperacusia y acúfenos, vámonos de Shopping

From Noisy to Quiet Shopping

Vivimos en un mundo ruidoso . Y el shopping es una de nuestras experiencias cotidianas ruidosas.

Hay grandes oportunidades para las marcas en crear una "huella sónica" de diferenciación que se puede implementar de manera integral a lo largo de varios puntos de contacto con los consumidores , como la publicidad , el uso del producto , en las tiendas , etc .


En otras palabras , el sonido se puede utilizar para inyectar asociaciones diferenciadoras en una marca . 
Esto esta todo muy bien , pero el inconveniente es que demasiadas empresas eligen deliberadamente subir el volumen con el objetivo de crear un ambiente frenético en el que la gente quiera gastar dinero.  

La falta de empatía mostrada por estas tiendas dá como resultado que una gran cantidad de personas  reciban sonido intenso  que los estresa y dificulta al  tratar de comprar.

Yo personalmente en muchas ocasiones tuve que abandonar las tiendas demasiado ruidosas con las manos vacías y a veces he tenido que abandonar incluso algunas marcas por excluir a las personas como yo con sus parlantes a maximo volumen , simulando un ambiente parecido a un night club .  


Puedo entender que algunas tiendas deseen crear energía a través de la música, pero la forma en que algunos van a tales extremos me parece inaceptable. 
Hay personas que prefieren la paz y la tranquilidad . Hay quienes tienen problemas de audición. quienes tienen una sensibilidad a ruidos fuertes .  

Hay ancianos que se estresan por música a alto volumen, hay niños y jóvenes cuya audición se perjudica cuando la música está demasiado alta . De hecho , hay un montón de personas que no se sienten cómodas con el exceso de ruido en las tiendas. 
Se podría decir que algunas marcas se dirigen a un segmento joven de la moda con una afinidad por el ambiente de la tienda ruidosa, llena de energía.  

En primer lugar , es probable que en realidad  se tienda a sobreestimar el grado y la cantidad de personas que lo prefieren así.

Consideren el hecho de que una gran cantidad de jóvenes hoy dia usan tapones para los oídos para ir a bailar y a recitales.  

Para un joven ir a una tienda de ropa no se asocia con un ambiente que necesite tapones para los oídos para que no traiga ninguna consecuencia  y en vez de eso se encuentra que tiene que sentirse estresado y molesto al intentar elegir la ropa.  

Por otra parte, los clientes jóvenes de una tienda de moda tienen hermanos, padres , abuelos y otros parientes que los acompañan . Lo mas probable es que estos se sientan desmotivados a realizar compras o  regalos si van a ser aterrorizados por ruidos fuertes tan pronto como ponen un pie en la tienda.  

Parece que es una política muy poco inteligente para las marcas involucradas. Sería interesante entender cómo llegaron a la conclusión de que el volumen extremadamente elevado era el camino a seguir . 
Cuando se trata de centros comerciales ¿es la tienda en particular la culpable? o es más bien la administración de los centros comerciales las que deben aplicar y hacer cumplir las directrices de ruido o los ajustes del nivel de sonido máximo permitido en las tiendas?  
Yo diría que el centro comercial debe garantizar que cualquier marca que alberga no se vaya a los extremos con sus sistemas de sonido . 
Por supuesto, incluso con una regulación del ruido en el lugar , será difícil encontrar  un nivel que haga a todos los compradores sentirse relajados y cómodos cuando quieren gastar su dinero .  

Una buena idea sería , por lo menos una vez al mes , ofrecer a los compradores ya sea un día completo o una tarde de compras tranquila no habiendo música permitida en ninguna tienda en todo el centro comercial.  

Esta será una gran oportunidad para que los compradores caminen a través de todo un centro comercial en un entorno tranquilo y silencioso, con dulzura . 
Compras Quiet, Compras Tranquilas todo el día , Quiet Night.  Shopping relajante, Silenciosa Night: Las alternativas de nombres son muchas.  

La idea central es mostrar empatía y amor a todos aquellos clientes que deseen realizar sus compras sin la estridencia inquietante de la música.

Si un Centro comercial puede a hacer esto una vez al mes , entonces  no debería ser demasiado dificil pedirlo en las tiendas participantes.  


Y probablemente crearía una amplia cobertura de los medios de comunicación y sería recibido por una gran cantidad de compradores financieramente fuertes .  

Si usted lee esto y está trabajando en un Centro comercial , por favor difunda esto en su oficina y comience una lluvia de ideas para tal iniciativa.

La pregunta es , ¿esto ya existe en algún lugar del mundo ? Si usted sabe de un centro comercial que hace algo similar , por favor, envíenos una línea para que podamos escribirles y celebrar esa iniciativa.


A los centros comerciales del mundo: ¡Por favor, prueben crear algo de espacio para los compradores que buscan un experiencia de compra calmante y relajante! Uds.están obligados a ser recompensados económicamente por una actividad tan inclusiva y de buen corazón .


fuente de la imagen: Aleksej Leonov
Fuente del trabajo: http://elevatingsound.com
Aleksej Leonov
Photo: Aleksej Leonov
Photo: Aleksej Leonov

Un buen plan de ejercicio para una persona de mediana edad

 

Un buen plan de ejercicios es como moverse en una fiesta en términos de opciones de entrenamiento, dice el doctor Michael Joyner, fisiólogo de la Clínica Mayo en Rochester, Minnesota

Es bueno pedalear o nadar (si usted es socio de un gimnasio) pero caminar es, fisiológicamente y logísticamente, el ejercicio más simple, dice el Dr. Joyner.  

Sólo hay que ponerse  zapatillas cómodas - no tienen porque  ser nuevas o caras - y uno gana la diferencia horaria entre simplemente camianr e ir al gimnasio, cambiarse, etc.  
Trate de caminar al menos media hora diariamente.

'' Treinta minutos de actividad física moderada vigorosa realizada la mayoría de los días es realmente el punto optimo en términos de tiempo-beneficio, desde el punto de vista epidemiológico'', dice el Dr. Joyner. "moderadamente vigoroso" significa que el corazón bombea al 50 a 70 por ciento de su velocidad máxima (que es, en términos generales, 220 menos su edad para los hombres, y un poco menos para las mujeres) o, dicho de otro modo y menos exactamente, el ritmo con el que se puede hablar con un compañero.

Estos 30 minutos no tienen que ser realizados de una sola vez, está bien  repartir el ejercicio durante el día "en tramos más pequeños'', dice el Dr. Joyner. Y, de hecho, como veremos, para ciertos grupos de personas, probablemente es más eficaz para hacerlo:


Se ha visto en un estudio de 2012, los adultos con alto riesgo de desarrollar hipertensión mejoraban su presión arterial con mayor eficacia si caminaban enérgicamente de 10 minutos tres veces al día mas que si caminaban enérgicamente una vez al día durante media hora.

'' El entrenamiento de esfuerzo es también una clave,'' Dr. Joyner dice,'' especialmente a finales de la edad media.  


Y es probable que ayude a prevenir la fragilidad a medida que envejecemos.'' Muchos gimnasios ofrecen clases de orientación de entrenamiento con pesas, o uno puede simplemente hacer flexiones y sentadillas en su sala de estar.  

Comience con una flexión de brazos, si eso es todo lo que puede hacer, y progrese hasta hacer 15 o 20.

Fuente: "The New York Times"
Fuente de la imagen abcsaline.blogspot.com

10 Essential Tips on How Parents with Tinnitus Can Protect Their Ears While Handling Screaming Babies



fuente de la imagen: www.cosasdepeques.com





Living with noise-induced tinnitus, which usually comes with a certain degree of sensitivity to noise, can be challenging at times.


Becoming a parent is a wonderfully transformational life experience. 
It also represents a challenge to those with tinnitus, since new-borns will often make quite a bit of noise that tends to be hard to anticipate.

I am living with noise-induced tinnitus, coupled with a fairly severe sensitivity to noise, and when I recently became a father I went through a period that was tough on my ears. 
I would like to share my experience and hopefully provide you with some useful tips on how parents with tinnitus should behave around screaming babies.


The easiest and most effective way to avoid having your ears hurt by erratic screams would be to wear earplugs 24/7. 

Depending on the type of earplugs used and how you feel about wearing them – inevitably, earplugs come with a sense of isolation – you can choose to what extent you decide to wear earplugs when around your child.


During the first year of my child’s life, I eventually found a way to deal with it. It has by no means been a perfect ride and, on various occasions, my ears were hurting due to having been surprised by loud screams in situations when I wasn’t wearing any ear protection.


I would like to give the following recommendations in terms of how to best protect your ears while enjoying life with a new-born.


1. During the first few years of a child’s life, you will naturally not be able to expect your kid to show empathy and consideration to you and your tinnitus. 

Up to the point when you will be able to get your child to understand why he/she should be careful about screaming around you, you will need to work out other solutions together with your partner.


2. It is essential for you to clearly communicate with your partner to make sure that he/she truly understands what your tinnitus means in practice, so that he/she can instinctively and quickly step in and help you out when difficult, noisy situations arise.


3. It is important for you to wear ear protection whenever necessary so that you don’t run the risk of further damaging your ears. 
The first period of a child’s life will often involve a lot of screaming, but remember that it’s temporary so keep focused on not further damaging your ears while thoroughly enjoying the magical first phase of your baby’s life.


4. While it’s absolutely nothing to be ashamed of, a lot of tinnitus sufferers may still feel conscious about openly using ear plugs or ear muffs for others to see. 

That feeling may especially come alive when dealing with your baby. 

You may wonder what people will think of you as a parent if you need to use ear plugs to protect yourself from your kid’s screaming.

It may lead to ignorant people making jokes about you behind your back. 

Of course, those people are the ones in the wrong. 
You not being able to cope with the screaming without protection because of your handicap by no means reflects anything about your capability as a parent. 

Keep focused on engaging with your baby while protecting your ears and don’t waste any time caring about what others around you may think.


5. Try to understand your baby’s behavior in order to anticipate the situations when he/she tends to get extra loud. E.g. if you learn that loud screams of joy comes when playing, then pre-empt the situation and insert a relevant amount of ear protection before playing. 
Depending on the severity of your tinnitus and the loudness of your child, choose the protection with the right level of decibel reduction.


6. If you wish to enjoy spending as much time as possible with your baby without the perceived isolation of wearing ear protection, then have a pair of ear muffs close-by. 

Whenever he/she starts to get loud, then you can quickly pop on the ear muffs without the extra time needed to insert ear plugs. 

The downside of this solution is that you will sometimes be exposed to loud noise before you manage to put on the ear muffs. In cases when you will not be picking up your baby, a quicker solution will be to just use your fingers to cover your ears.


7. If you would rather want to be safe than sorry and wear protection throughout extended periods of spending time with your child, then it’s highly recommendable to get a pair of custom-molded ear plugs with a decibel filter that reduces the noise in a linear fashion, allowing you to hear your child in a more natural way while being protected from the most damaging noise levels. Commonly, you will be able to choose between filters that reduce the noise by 15 decibels, 25 decibels etc. 

Custom-fitted ear plugs are comfortable to wear and they don’t make you feel as isolated as with other types of ear protection. 
The downside is that you won’t receive the same level of protection as with e.g. foam ear plugs and ear muffs.


8. It’s very important for you to take care of your ears during the, generally speaking, pretty loud baby phase. 
Hence, it is well worth the investment to buy multiple pairs of ear plugs and ear muffs. 
If you e.g. know that your baby sometimes screams very loudly while changing diapers then always keep a pair of ear muffs handy in the bathroom. 
If you have experienced outbursts of prolonged screaming while traveling in the car, then keep some fresh ear plugs or a pair of ear muffs with a high level of noise reduction inside the car. And so on.


9. When visiting friends and family, communicate clearly with them about your tinnitus condition and how they could be of help if you were to be in a situation when your baby is noisy without you having protected your ears. 
Don’t underestimate how much your loved ones would like to help you out so make sure to enable them to take some burden off your chest when stressful situations arise.


10. Having tinnitus means that noise will be extra stressful to you. In order to care for your baby in a solid, non-stressed way, don’t hesitate to take the extra time needed to put on ear protection before you start to console your child. 
It is safer for your ears and it will be safer to handle the situation without the stress that the noise will cause due to hurting ears.


I hope these tips will be helpful to you in your new-found role as a parent in order to save your ears from being more damaged. If you have some additional tips not mentioned here, please comment below or drop us a line at hello@elevatingsound.com.

August 5, 2013 by Magnus

 See more at: http://elevatingsound.com/10-essential-tips-on-how-parents-with-tinnitus-can-protect-their-ears-while-handling-screaming-babies/#sthash.2SivLpvi.dpuf

Fuente:  http://elevatingsound.com

Acúfenos: Seccion Investigacion de tratamientos farmacológicos: Pérdida de la audición inducida por el ruido : ¿un nuevo medicamento potencial?

Pérdida de la audición inducida por el ruido  : ¿un nuevo medicamento potencial?

Lunes, 16 de septiembre 2013 
por James Robins
 

Una nueva Investigación  ha arrojado luz sobre una sustancia llamada PEDF que desempeña un papel importante en la protección de nuestra audición frente a   daños por ruido.
Tracey Pollard de nuestro equipo de Investigación Biomédica nos dice más sobre esta investigación y su potencial para contribuir al desarrollo de fármacos que pueden proteger contra
la perdida auditiva inducida por ruido.
 
Anonymous face..El potencial endococlear
Las células ciliadas , son las células sensoriales del oído  interno , asientan en la parte superior de una membrana de la cóclea , que está conectada a la parte exterior del oido interno y se encarga de llevar la información del sonido en la cóclea .

 
La membrana forma el límite de la escala media , un compartimento separado dentro de la cóclea ( véase el diagrama ) , donde las células ciliadas están rodeadas de un fluido llamado endolinfa .
Este líquido contiene una concentración muy alta de iones de potasio en comparación con otras zonas de la cóclea y por lo tanto esta mucho más cargado eléctricamente  - esta diferencia en la carga se llama el potencial endococlear .
A diagram showing the 'scala media' within the cochlear. Un diagrama que muestra la " escala media ' dentro del fluido coclear.

Dentro de las celulas  ciliadas internas hay una concentración muy baja de iones de potasio en comparación con otras partes del oído interno , lo que significa que la diferencia de carga entre la endolinfa y el cabello célula es aún más grande .

 
Esta diferencia es crucial para permitir que las señales del oido interno puedan  ser enviadas correctamente al cerebro .
Si el potencial endococlear se pierde ,
se produce. una pérdida de la audición de aproximadamente 40 dB.
Esto es equivalente a una pérdida de audición moderada en la que una persona tendría problemas para escuchar una conversacion claramente sin utilizar audífonos.
El potencial es mantenido por una estructura en la escala media llamada la estría vascular .Esta estructura , compuesta de muchas capas de células agrupadas muy juntas , formando una barrera entre la endolinfa en el interior de la escala media y el torrente sanguíneo que circula fuera de ella .
El movimiento de los iones de potasio en la endolinfa se organiza, utilizando una serie de bombas incluidas en las membranas celulares .

 C
omo las células están tan estrechamente agrupadas , el fluido no puede  fácilmente fugarse entre ellas y así una vez que el potasio está dentro de la endolinfa , no puede salir - al menos no a través de la estría vascular.

 

PEDFLas células se mantienen unidas tan fuertemente por  estructuras conocidas como uniones estrechas mediante  interacciones entre ciertas proteínas sobre las superficies de estas células , que se unen fuertemente entre sí y brindan seguridad a todos los espacios entre las células por donde una fuga podría ocurrir .

 
Mientras tanto, otro tipo de células asienta en la estría vascular -  que tienen forma de un árbol ramificado -que les permite ponerse en contacto con muchas células de la estría vascular y comunicarse con ellas .Estas células producen una sustancia llamada PEDF ( factor de crecimiento del epitelio pigmentado ) , y este actúa sobre las células de la estría vascular para hacerlas producir las proteínas necesarias para formar las uniones estrechas .
Investigadores de los EE.UU. han publicado recientemente una investigación sobre el impacto de la exposición a ruidos intensos de este sistema, en un modelo animal .Lo que encontraron fue que la exposición al ruido hace que la estructura bien entramada de la estría vascular tienda a descomponerse.Esto ocurre porque las células de tipo arboreo  cambian de forma , y se vuelven cada vez menos ramificadas y así  dejan de ponerse en contacto con  de la estría vascular y  dejan de producir suficiente PEDF .
A su vez , las células en la estría vascular dejan de producir suficientes proteínas de unión estrecha y  las células se mantienen mucho menos juntas.La endolinfa entonces se filtra entre las células y entonces el potasio se escapa de la endolinfa , destruyendo el potencial endococlear  y causando la pérdida de audición .
Sin embargo , los investigadores también encontraron que si se administra PEDF a los animales justo antes de exponerlos al ruido, este PEDF extra es capaz de proteger a la estría vascular de este daño y así preservar la audición de los animales.
Esto sugiere que el PEDF (que ya está siendo investigado como un tratamiento potencial para la enfermedad cardíaca y el cáncer ) y las células que lo producen en la cóclea son objetivos prometedores para el desarrollo de drogas para proteger contra el daño inducido por ruido en el oído interno.


Fuente: Action on Hearing
http://www.actiononhearingloss.org.uk

 


lunes, 23 de septiembre de 2013

Fisiologia auditiva:" Brain Makes Call On Which Ear Is Used for Cell Phone"

Brain Makes Call On Which Ear Is Used for Cell Phone

May 16, 2013 — If you're a left-brain thinker, chances are you use your right hand to hold your cell phone up to your right ear, according to a newly published study from Henry Ford Hospital in Detroit.

The study -- to appear online in JAMA Otolaryngology-Head & Neck Surgery  shows a strong correlation between brain dominance and the ear used to listen to a cell phone. 

More than 70% of participants held their cell phone up to the ear on the same side as their dominant hand, the study finds.

Left-brain dominant people who account for about 95% of the population and have their speech and language center located on the left side of the brain are more likely to use their right hand for writing and other everyday tasks.

Likewise, the Henry Ford study reveals most left-brain dominant people also use the phone in their right ear, despite there being no perceived difference in their hearing in the left or right ear. And, right-brain dominant people are more likely to use their left hand to hold the phone in their left ear.

"Our findings have several implications, especially for mapping the language center of the brain," says Michael Seidman, M.D., FACS, director of the division of otologic and neurotologic surgery in the Department of Otolaryngology-Head and Neck Surgery at Henry Ford.


"By establishing a correlation between cerebral dominance and sidedness of cell phone use, it may be possible to develop a less-invasive, lower-cost option to establish the side of the brain where speech and language occurs rather than the Wada test, a procedure that injects an anesthetic into the carotid artery to put part of the brain to sleep in order to map activity."

He notes that the study also may offer additional evidence that cell phone use and tumors of the brain, head and neck may not necessarily be linked.

Since nearly 80% of people use the cell phone in their right ear, he says if there were a strong connection there would be far more people diagnosed with cancer on the right side of their brain, head and neck, the dominant side for cell phone use. 

It's likely, he says, that the development of tumors is more "dose-dependent" based on cell phone usage.

The study began with the simple observation that most people use their right hand to hold a cell phone to their right ear. 

This practice, Dr. Seidman says, is illogical since it is challenging to listen on the phone with the right ear and take notes with the right hand.

To determine if there is an association between sidedness of cell phone use and auditory or language hemispheric dominance, the Henry Ford team developed an online survey using modifications of the Edinburgh Handedness protocol, a tool used for more than 40 years to assess handedness and predict cerebral dominance.

The survey included questions about which hand was used for tasks such as :
  1. writing; 
  2. time spent talking on cell phone; 
  3. whether the right or left ear is used to listen to phone conversations; 
  4. and if respondents had been diagnosed with a brain or head and neck tumor.

It was distributed to 5,000 individuals who were either with an otology online group or a patient undergoing Wada and MRI for non-invasive localization purposes.

On average, respondents' cell phone usage was 540 minutes per month. 

The majority of respondents
  1.  (90%) were right handed, 
  2. 9% were left handed and 
  3. 1% was ambidextrous.

Among those who are right handed, 
  • 68% reported that they hold the phone to their right ear, while
  • 25% used the left ear and 
  • 7% used both right and left ears. 

For those who are left handed, 
  • 72% said they used their left ear for cell phone conversations, while 
  • 23% used their right ear and 
  • 5% had no preference.
The study also revealed that having a hearing difference can impact ear preference for cell phone use.

In all, the study found that there is a correlation between brain dominance and laterality of cell phone use, and there is a significantly higher probability of using the dominant hand side ear.

Studies are underway to look at tumor registry banks of patients with head, neck and brain cancer to evaluate cell phone usage.

Controversy still exists around a potential association of cell phone use and tumors. 

Until this is fully understood, Dr. Seidman advises using hands-free modes for calls rather than holding a phone up to the side of the head.
Fuente: JAMA Otolaryngology-Head & Neck Surgery
Fuente de la imagen:  http://sweetwaterlibraries.com/sclsblogs/readeronthesamepage/?p=5227

Fisopatologia auditiva:"Hearing Loss from Loud Blasts May Be Treatable"

Hearing Loss from Loud Blasts May Be Treatable

July 1, 2013 — Long-term hearing loss from loud explosions, such as blasts from roadside bombs, may not be as irreversible as previously thought, according to a new study by researchers at the Stanford University School of Medicine.


Perforation of the tympanic membrane of a mouse after blast exposure. Image (A) was taken immediately following a blast; perforations were always seen as in this representative example (green arrows). The malleus (m) is identified. (B) is after 14 days, and (C) after 28 days. (Credit: Cho et al. Mechanisms of Hearing Loss after Blast Injury to the Ear. PLoS ONE, 2013; 8 (7): e67618 DOI: 10.1371/journal.pone.0067618)



Using a mouse model, the study found that loud blasts actually cause hair-cell and nerve-cell damage, rather than structural damage, to the cochlea, which is the auditory portion of the inner ear. 

This could be good news for the millions of soldiers and civilians who, after surviving these often devastating bombs, suffer long-term hearing damage.

"It means we could potentially try to reduce this damage," said John Oghalai, MD, associate professor of otolaryngology and senior author of the study, published July 1 in PLOS ONE

If the cochlea, an extremely delicate structure, had been shredded and ripped apart by a large blast, as earlier studies have asserted, the damage would be irreversible. 

(Researchers presume that the damage seen in these previous studies may have been due to the use of older, less sophisticated imaging techniques.)

"The most common issue we see veterans for is hearing loss," said Oghalai, a scientist and clinician who treats patients at Stanford Hospital & Clinics and directs the hearing center at Lucile Packard Children's Hospital.

The increasingly common use of improvised explosive devices, or IEDs, around the world provided the impetus for the new study, which was primarily funded by the U.S. Department of Defense.

Among veterans with service-connected disabilities, tinnitus -- a constant ringing in the ears -- is the most prevalent condition.

Hearing loss is the second-most-prevalent condition. 

But the results of the study would prove true for anyone who is exposed to loud blasts from other sources, such as jet engines, air bags or gunfire.

More than 60 percent of wounded-in-action service members have eardrum injuries, tinnitus or hearing loss, or some combination of these, the study says. 

Twenty-eight percent of all military personnel experience some degree of hearing loss post-deployment. 

The most devastating effect of blast injury to the ear is permanent hearing loss due to trauma to the cochlea. 

But exactly how this damage is caused has not been well understood.

The ears are extremely fragile instruments. 

Sound waves enter the ear, causing the eardrums to vibrate. 

These vibrations get sent to the cochlea in the inner ear, where fluid carries them to rows of hair cells, which in turn stimulate auditory nerve fibers. 

These impulses are then sent to the brain via the auditory nerve, where they get interpreted as sounds.

Permanent hearing loss from loud noise begins at about 85 decibels, typical of a hair dryer or a food blender. 

IEDs have noise levels approaching 170 decibels.

Damage to the eardrum is known to be common after large blasts, but this is easily detected during a clinical exam and usually can heal itself -- or is surgically repairable -- and is thus not typically the cause of long-term hearing loss.

In order to determine exactly what is causing the permanent hearing loss, Stanford researchers created a mouse model to study the effects of noise blasts on the ear.

After exposing anesthetized mice to loud blasts, researchers examined the inner workings of the mouse ear from the eardrum to the cochlea.

The ears were examined from day one through three months. A micro-CT scanner was used to image the workings of the ear after dissection.

"When we looked inside the cochlea, we saw the hair-cell loss and auditory-nerve-cell loss," Oghalai said.

"With one loud blast, you lose a huge number of these cells. 

What's nice is that the hair cells and nerve cells are not immediately gone. 
The theory now is that if the ear could be treated with certain medications right after the blast, that might limit the damage."

Previous studies on larger animals had found that the cochlea was torn apart and shredded after exposure to a loud blast. 

Stanford scientists did not find this in the mouse model and speculate that the use of older research techniques may have caused the damage.

"We found that the blast trauma is similar to what we see from more lower noise exposure over time," said Oghalai. "We lose the sensory hair cells that convert sound vibrations into electrical signals, and also the auditory nerve cells."

Much of the resulting hearing loss after such blast damage to the ear is actually caused by the body's immune response to the injured cells, Oghalai said. 

The creation of scar tissue to help heal the injury is a particular problem in the ear because the organ needs to vibrate to allow the hearing mechanism to work. Scar tissue damages that ability.

"There is going to be a window where we could stop whatever the body's inflammatory response would be right after the blast," Oghalai said. "We might be able to stop the damage. This will determine future research."

In addition to the Department of Defense, the study was funded by the National Institutes of Health (grants K08DC006671 and P30DC010363) and Chosun University in South Korea.

The first author of the study, Sung-Il Cho, MD, assistant professor at Chosun University, was working at Stanford during the study. Other Stanford authors were graduate students Simon Gao, Jongmin Baek and David Jacobs; senior research scientist Anping Xia, MD, PhD; research technician Rosalie Wang; research associate Felipe Salles, PhD; computer programmer Patrick Raphael; and research coordinator Homer Abaya
_______________________________________________________________________________________________
Fuente: 

Acúfenos: Fisiología Auditiva: "Brain Picks out Salient Sounds from Background Noise by Tracking Frequency and Time, Study Finds"

Brain Picks out Salient Sounds from Background Noise by Tracking Frequency and Time, Study Finds

July 23, 2013 — New research reveals how our brains are able to pick out important sounds from the noisy world around us. The findings, published online today in the journal eLife, could lead to new diagnostic tests for hearing disorders.


Noisy crowd. New research reveals how our brains are able to pick out important sounds from the noisy world around us. (Credit: © PDU / Fotolia)
 
Our ears can effortlessly pick out the sounds we need to hear from a noisy environment -- hearing our mobile phone ringtone in the middle of the Notting Hill Carnival, for example -- but how our brains process this information (the so-called 'cocktail party problem') has been a longstanding research question in hearing science.

Researchers have previously investigated this using simple sounds such as two tones of different pitches, but now researchers at UCL and Newcastle University have used complicated sounds that are more representative of those we hear in real life. 

The team used 'machine-like beeps' that overlap in both frequency and time to recreate a busy sound environment and obtain new insights into how the brain solves this problem.

In the study, groups of volunteers were asked to identify target sounds from within this noisy background in a series of experiments.

Sundeep Teki, a PhD student from the Wellcome Trust Centre for Neuroimaging at UCL and joint first author of the study, said: "Participants were able to detect complex target sounds from the background noise, even when the target sounds were delivered at a faster rate or there was a loud disruptive noise between them."

Dr Maria Chait, a senior lecturer at UCL Ear Institute and joint first author on the study, adds: "Previous models based on simple tones suggest that people differentiate sounds based on differences in frequency, or pitch. 

Our findings show that time is also an important factor, with sounds grouped as belonging to one object by virtue of being correlated in time."

Professor Tim Griffiths, Professor of Cognitive Neurology at Newcastle University and lead researcher on the study, said: "Many hearing disorders are characterised by the loss of ability to detect speech in noisy environments. 

Disorders like this that are caused by problems with how the brain interprets sound information, rather than physical damage to the ear and hearing machinery, remain poorly understood.

"These findings inform us about a fundamental brain mechanism for detecting sound patterns and identifies a process that can go wrong in hearing disorders. 

We now have an opportunity to create better tests for these types of hearing problems."

The research was funded by the Wellcome Trust and Deafness Research UK.
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Fuente: http://www.sciencedaily.com/releases/2013/07/130723113743.htm

Acúfenos: Sección fisiopatologia auditiva: "Starring Role Discovered for Supporting Cells in Inner Ear"

Starring Role Discovered for Supporting Cells in Inner Ear

July 25, 2013 — Researchers have found in mice that supporting cells in the inner ear, once thought to serve only a structural role, can actively help repair damaged sensory hair cells, the functional cells that turn vibrations into the electrical signals that the brain recognizes as sound.
The study in the July 25, 2013 online edition of the Journal of Clinical Investigation reveals the rescuing act that supporting cells and a chemical they produce called heat shock protein 70 (HSP70) appear to play in protecting damaged hair cells from death. 

Finding a way to jumpstart this process in supporting cells offers a potential pathway to prevent hearing loss caused by certain drugs, and possibly by exposure to excess noise. 

The study was led by scientists at the National Institutes of Health.
Over half a million Americans experience hearing loss every year from ototoxic drugs -- drugs that can damage hair cells in the inner ear. 

These include some antibiotics and the chemotherapy drug cisplatin. 

In addition, about 15 percent of Americans between the ages of 20 and 69 have noise-induced hearing loss, which also results from damage to the sensory hair cells.
Once destroyed or damaged by noise or drugs, sensory hair cells in the inner ears of humans don't grow back or self-repair, unlike the sensory hair cells of other animals such as birds and amphibians.

This has made exploring potential pathways to protect or regrow hair cells in humans a major focus of hearing research.

"If you're looking to protect hair cells, you should be looking at supporting cells," said senior author Lisa Cunningham, Ph.D., whose laboratory of sensory cell biology at the National Institute on Deafness and other Communication Disorders (NIDCD), a component of NIH, led the study. 

"Our study indicates that when the inner ear is under stress, the cell that responds by generating protective proteins is not a hair cell, but a supporting cell."
Earlier work by Dr. Cunningham's group and other labs had shown that HSP70 -- a protein produced in the inner ear after exposure to stressors such as environmental toxins, oxidative stress, chemical toxins, and noise -- can protect hair cells. 

However, the mechanism wasn't fully understood.
In this study, researchers exposed mouse utricles to heat and then rapidly preserved them. 

The scientists found robust expression of HSP70; however, microscopy techniques showed that the protein was located only in the supporting cells, not the hair cells.
Further experiments showed that the supporting cells don't keep the HSP70 to themselves -- they secrete HSP70, which can then protect neighboring hair cells. 

When utricles that had not undergone heat shock were placed in the same culture as heat-shocked utricles, the hair cells in the untreated utricle were protected from cell death after exposure to an ototoxic antibiotic. 

Most likely, this could only have happened if the heat-shocked supporting cells shared their HSP70, since the non-heat shocked utricles didn't generate HSP70 of their own. 

Further, when the researchers used methods to prevent heat-shocked utricles from producing or secreting HSP70, this protective effect disappeared.
The researchers expected to see hair cells eventually take up the HSP70 produced by heat-shocked supporting cells, but this didn't happen. 

Using three different laboratory techniques, they couldn't find a trace of HSP70 inside hair cells in the mouse utricles.
Dr. Cunningham says this could mean one of two things. 

One possibility is that only tiny amounts of HSP70, at levels too low to be detected, are taken up by the hair cells. 
The other is that HSP70 works outside the cell, perhaps attaching to a receptor that doesn't need to be taken up into the hair cell to activate a protective signaling pathway. 

Follow-up work in Dr. Cunningham's lab will try to identify such a receptor.
Results from other labs studying supporting cells in the inner ear have shown that these cells can also kill hair cells that are too damaged for repair. 

"When a hair cell is under stress, it looks like a supporting cell is the one that decides whether it's going to live or die," said Dr. Cunningham.
Still to be explained are how the hair cell signals that it's in trouble, how the supporting cell senses the signal and, ultimately, how the supporting cell decides that it's going to save a hair cell or kill it.
However, a complete understanding of the protective mechanism isn't required to harness its clinical potential. 

Dr. Cunningham and her colleagues, in collaboration with a clinical team at NIDCD, are designing a human trial to look at ways to induce the production of HSP70 in the inner ear before ototoxic drug treatment.
The research was supported by NIDCD intramural funds DC000079 and NIDCD grants DC007613 and DC07613-SI.
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Fuente:  http://www.sciencedaily.com/releases/2013/07/130725125306.htm

Acúfenos: Características: "Perceptual Components of Tinnitus Severity "

Perceptual Components of Tinnitus Severity
(Abstract of ARO Meeting Denver, Colorado)
Mary Meikle1, James Henry2, Susan Griest1, Barbara Stewart1
 

Oregon Health & Science University, 2Portland VA Medical Center, Portland, OR. USA




Most existing questionnaires for assessing the severity and negative impact of tinnitus tend to emphasize functional or emotional effects of tinnitus. 


While such measures are important for diagnostic purposes and as outcome measures, they require time periods of several days to several weeks or longer for observation of meaningful changes following treatment.
 

More rapid evaluation of treatment outcomes can be obtained using patients' reports of the perceptual characteristics of tinnitus such as its loudness, salience, unpleasantness, intrusiveness, and the percentage of time the tinnitus sensations are perceived. 

However, the extent to which such perceptual attributes of tinnitus are appropriate indicators of the clinical severity of tinnitus has received relatively little systematic attention. 

To maximize measurement sensitivity, we designed a 43-item questionnaire to quantify patients' responses concerning functional, emotional and perceptual aspects of tinnitus, using a 0-10 point response scale for each question. 

A total of 327 subjects with varying levels of tinnitus, recruited from a diverse group of patients attending clinics in three locations (Oregon, Ohio, Florida), responded to the questionnaires before and after receiving treatment. 

As expected, the perceptual attributes listed above were positively related to global measures of tinnitus distress, including (1) a Visual Analog Scale and (2) the question "How much of a problem is your tinnitus?" (response levels: 0=Not a problem; 1=Small problem; 2=Moderate problem; 3=Big problem; 4=Very big problem). 

Effect sizes for the perceptual measures (computed for subjects reporting treatment benefi t) ranged from 0.49- 1.50. 

Additional data will be presented concerning the ability of perceptual measures to serve as reliable, sensitive outcome measures for studies that require rapid evaluation of tinnitus treatments having immediate effects, such as stimulation with electrical, magnetic, or acoustic stimuli. 
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Fuente:http://www.eutinnitus.com/ActLit_lxp.php 

Acúfenos: Sección est"udios: "Cortical and subcortical fMRI of unilateral tinnitus."

Cortical and subcortical fMRI of unilateral tinnitus.
(Abstract of ARO Meeting Denver, Colorado)
Cris Lanting1,2, Emile de Kleine1,2, Hilke Bartels1, Dave Langers1,2, Pim van Dijk1,2
1Department of Otorhinolaryngology / Head and Neck Surgery, University Medical Center Groningen,
2Fac. of Medical Sciences, School of Behavioral and Cognitive Neurosciences, University of Groningen 




The current understanding of possible mechanisms of tinnitus generation is still poor. 


Our goal is to find a possible neural correlate of tinnitus, using fMRI.

In this work we used 10 patients (5 male) with unilateral tinnitus (5 left sided, 5 right sided) and 9 healthy subjects (4 male). 


Subjects had no or minor hearing deficits in both ears (max. 30 dB HL). 

Experiments were performed on a 3T Philips Intera scanner. 

41 coronal slices (2 mm) were acquired using a matrix of 128x128 voxels (1.75 x 1.75 mm2) using sparse sampling (TR=10 s). 

Stimuli consisted of right and left stimulation with levels of 40 and 70 dB (SPL) of rippled noise.
 

Data were realigned and normalized to a custom made template using SPM5. 

First level analysis was performed using multiple regression and regions of interest (ROI) of the auditory pathway were defi ned (cortex, MGB, IC, SOC and CN).
 

Percent signal changes were obtained for each condition for each region and symmetry indices were obtained. 

A second level analysis was performed using an ANOVA design to assess group differences and group-by-level interactions.
 

Results from the ROI analysis indicate that for the control group the cortex and inferior colliculus responded strongest to contralateral stimuli.

A difference was observed between the two tinnitus patient groups. 

The left sided tinnitus group showed a predominant response towards ipsilateral stimuli at the cortex while the right sided tinnitus group responded more like the control group.

A general trend of higher activation in the inferior colliculus as response to stimuli was observed in tinnitus patients compared to controls.

Our data suggest that there are differences in activation on cortex level and inferior colliculus level between the control group and the patient groups. 


Analysis of other nuclei will be performed. 
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Fuente:  http://www.eutinnitus.com/ActLit_lxp.php