Sound or Silence? The Pros and Cons of Cochlear Implants

Cochlear implants (CI) have been in use for several decades, yet there is still an active controversy surrounding these devices. While some people strongly advocate for the positive effect on an individual’s life, others claim that implants are dangerous both to individual health and to deaf culture at large [1].

PRO
Even though a CI cannot provide 100% hearing capability, it enables the individual to hear and understand most sounds. A cochlear implant does not amplify sounds like common external hearing aids, but stimulates the auditory nerve. The implant essentially replaces the function of the hair cells in the inner ear that usually register sound vibrations.  
Most importantly, a CI enables the individual to hear itself and thus learn to speak and articulate, and thus an implant helps to communicate with hearing people who do not know sign language. It also saves from  lip reading and generally depending on others for hearing help.
Another great advantage of having a CI for young people is that it can help them fully participate in mainstream schools and society, as well as broaden their career choices. While they may still be limited, the limitation won’t be as severe or as disabling as if they had no hearing choices available to them.
Being able to hear is also a measure of safety: the ability to locate sounds allows you to be more aware of perilous situations and hear impending danger such as a car coming from behind.

Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=29025007

CONTRA
CI require a surgical insertion and obviously surgery of itself always bears risks. Since the device has become available, risks have been minimized, however, complications may include occasional facial numbness or minor facial paralysis. Among individuals wearing a CI, there is also higher incidence of bacterial meningitis than for the general population. Thus an immunization is recommended. The body may also reject the implant, which could require removal or further surgery.
It is important to keep in mind that a CI doesn’t guarantee that a person will be able to hear and speak at a normal level. In some cases, the person with the implant can only hear some environmental sounds. Particularly for adults who receive the implant, electronic signals might not register fully and some hearing impairment may still occur. Also it is important to acknowledge that the auditory cortex is not used to process sound in the same way if a person has been deaf for a long time, so a CI wouldn't help much. 
Thus parents of hearing disabled children are urged  to make a decision as soon as possible for their child. Most people with an implant still need special help in learning to speak and in many cases they will still be stigmatized. Even though they can hear and speak, their hearing capabilities are not the same as a hearing person's [2]. Luckily, the devices are getting better and improved sound perception lets the wearer of CI integrate better into mainstream society.
Obviously, it takes time to get used to the implant and especially in the beginning, many need to get the CI reprogrammed according to their needs. Also, people with CI are limited on some physical activities, especially those involving contact with water, as this could damage the implant.

Controversy in Deaf Society
The primary controversy regarding CI concerns the definition of deafness as a disability. Recently journalist Enno Park gave a talk at the Berlin re:publica conference , where he spoke about his very personal view on the two (hearing and non-hearing) sides of society [3].
The medical community generally regards deafness as a disability that should be treated, and mainstream (hearing) society is of the opinion that hearing allows for a more fulfilling life. Meanwhile, many individuals who are deaf, as well as others who are familiar with non-hearing society feel that deafness is a cultural identity rather than a disability [4]. As a result, they feel that CI implies that there is something wrong with them that needs to be fixed, and that living as a person with a hearing impairment is inherently less fulfilling than as a "normal" person. Thus, these members of the community perceive putting something technical in their brains as serious affront.
Within the non-hearing community, there is a long history of disagreement: Some signing people feel that CI wearers are betraying their culture. Some even go as far as to describe implantation of children as “child abuse”. Also, with more people wearing CI, the need for sign-language interpreters decreases to the disadvantage of those who still rely on their services. On the other hand, parents that do not want their children implanted have to deal with hostility not only from the hearing community, but also from CI-wearers.




--> Get an idea how sound is perceived, through a CI! <--




Interestingly, the attitude towards sign language differs from country to country. In Germany and France, most people working in deaf education even don't speak sign language, and emphasis is placed on children learning to lip read [2,3]. In contrast, in the US, every police department should have one or more interpreters available on call [5]. It is likely that these attitudes and values will change over time, both with the rise of improving hearing technology and activism from within the deaf community.
The decision to receive a CI is a very personal one that should be considered with the help of a medical professional. Every parent with a hearing disabled child needs to decide for themselves what the best choice for their situation is.

Claudia Willmes
PhD Alumna, AG Eickholt / AG Schmitz

Background:
From 2007 to 2008 I worked at the Institute le Bruckhof in Strasbourg, France -  an institution for hearing disabled children, where many children wore cochlear implants [6]. They received special training in learning language and were encouraged to read lips instead of using sign language. However, I also took classes in an adult education center to learn DGS (German sign language) for one year and attended the university in Strasbourg to learn LSF (French sign language). Thus, I heard opinions from all sides: the hearing, the hearing disabled and signing, and those wearing CI.

[1] www.nad.org
[2] personal communication
[3] talk by Enno Park https://bit.ly/2K3MO8P
[4] Ohio University, The Institute for Applied & Professional Ethics https://bit.ly/2wxdrBg
[5] U.S. Department of Justice  https://www.ada.gov/q%26a_law.htm
[6] www.bruckhof.org/
 

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Music and the Rhythmic Brain

Music is universal and has no boundaries. But why has music evolved when there seems to be no real purpose for it like survival or reproduction? 

via pixabay

Researchers believe that music is important to human evolution in various ways: by helping babies to learn a language, aiding in the transfer of knowledge or history over generations and social bonding. Music is much more complex than just sound - it is organized, melodious and rhythmic.

Physics of Music
Music comprises fundamental elements such as pitch, tempo, timbre, key and intensity. Being a singer, I was interested in knowing the differences in the structure of distinct kinds of music and how our brains perceive them. Doing some reading, I found out that there are two major musical tunings: 'just intonation' and 'equal temperament'.

WITHOUT MUSIC, LIFE WOULD BE A MISTAKE.

- FRIEDRICH NIETZSCHE -

 
Western classical and most modern music are based on a 12-tone equal temperament system. In this musical tuning, 12 equal intervals divide the octave, with the same frequency ratio between adjacent notes. Just intonation is a musical tuning in which the octave consists of seven frequency notes which are members of harmonic series and are related by ratios of whole numbers. Indian classical music, bagpipes and barbershop quartets are based on the just intonation system [1].

Perception of Music
Have you ever wondered what is going on in your brain while you are listening to Beethoven’s 9th symphony? How are you able to disentangle the complex sounds of different instruments? And why do you feel this indescribable bliss while listening to music? How exactly do our brains process music?
Processing of music activates different prefrontal, temporal and cerebellar brain regions. Music or sound are basically the vibration of air molecules which traverses the ear drum, through the middle ear to the inner ear, where the frequency and intensity of sound waves are encoded as electrical signals by hair cells. These signals are relayed to the auditory brainstem and midbrain, where low-level processing such as interaural level and time differences occurs. This information about sound is then sent to the thalamus and to the primary auditory cortex.

UNCERTAINTY MAKES MUSIC BEAUTIFUL

Feature detection – such as pitch, rhythm and other higher-order processing – happens in the primary auditory cortex. Neurons of the auditory cortex can respond to a range of sound frequencies. These are tonotopically organized; meaning frequencies ranging from low to high are represented in the brain by neighboring regions [2]. During the perception of music, multiple sounds are processed simultaneously. The auditory system forms links between the sounds based on the fundamentals such as pitch, timing, harmony as well as the spatial location of the sound [3]. In addition, processing lyrics requires the brain's language centers.

Melody and Rhythm Processing
Studies implicate the secondary auditory cortex in melody processing, which involves comparing an anomaly or out-of-tune pitch in a melody with previous music knowledge [4]. On the other hand, the motor areas, parietal cortex, frontal cortex and cerebellum are involved in rhythm processing. A study has shown that the electrical activity in the brain occurs in phase with the beats of the rhythm [5]. An intriguing aspect of music processing is the activation of the visual cortex. Research shows that music evokes visual imagery in the listener’s mind according to the variation in the music [6].
Listening to music also activates the pleasure center in the brain (nucleus accumbens), which evokes the strong “blissful, intoxicating” feeling [7]. In Indian classical music, a ‘raga’, or series of four or more notes (in harmonic series), is known to evoke specific emotions inside the mind of the listener [8]. Our brains are also constantly predicting upcoming sequences in a song based on patterns and beats, creating a sense of anticipation. But scientists have found out that some aspect of surprise or uncertainty in music also increases its aesthetic beauty [9]!

LISTENING TO MUSIC INDUCES VISUAL IMAGERY

Music production requires complex motor control movements such as timing (as in rhythm), sequencing and spatial organization of motor movements (as in playing the notes on musical instruments). This involves various brain regions such as the primary motor cortex and the supplementary motor area, cerebellum, and basal ganglia [10].  An interesting study showed that, while playing a duet, brain waves become synchronized between the two guitarists [11]. Music indeed has an immense power on our minds that transcends our understanding!

[1] http://bit.ly/1QUrLEy
[2] Lauter et al, Hear Res, 1985
[3] Deutsch, Front Biosci, 2007
[4] Brattico et al, Brain Res, 2006
[5] Snyder and Large, Brain Res Cogn Brain Res, 2005
[6] Zatorre and Helpern, Neuron, 2005
[7] Salimpoor et al, Nat Neurosci, 2011
[8] http://bit.ly/1Q87JFf
[9] http://bit.ly/1JORqwv
[10] Zatorre et al, Nat Rev Neurosci, 2007.
[11] Sänger et al, Front Hum Neurosci, 2012

by Aarti Swaminathan, PhD Student AG Schmitz
This article originally appeared 2015 in CNS Volume 8, Issue 2, Art. And the Brain.