Personal Music Players & Hearing


Glossary over Personal Music Players & Hearing


A class of natural or man-made substances, such as penicillin, that kill or inhibit the growth of some micro-organisms. (Source: GreenFacts, based on CoRIS, Glossary  )



Any substance that prevents or reduces damage caused by free-radicals (highly reactive chemicals containing oxygen) which attack other molecules and modify their chemical structure.

Antioxidants are commonly used as preservatives in food or cosmetics. Well-known antioxidants include vitamins A, C, and E. (Source: GreenFacts)


Bacteria are a major group of micro-organisms that live in soil, water, plants, organic matter, or the bodies of animals or people. They are microscopic and mostly unicellular, with a relatively simple cell structure.

Some bacteria cause diseases such as tetanus, typhoid fever, pneumonia, syphilis, cholera, and tuberculosis.

Bacteria play a role in the decomposition of organic matter and other chemical processes. (Source: GreenFacts)



Any one of a group of diseases that occur when cells in the body become abnormal and have the potential to spread and establish growth in nearby tissues and other parts of the body (malignancy). (Source: GreenFacts )



The decibel (dB) is a unit used to measure sound intensity and other physical quantities. A decibel is one tenth of a bel (B), a unit named after Graham Bell, the inventor of the telephone. Its logarithmic scale is convenient to represent the entire range of human hearing.

The decibel of sound pressure level (dB SPL) takes as a reference the minimum sound pressure level that the average human ear can detect. The smallest audible sound to humans is typically 0 dB SPL (hearing threshold). In practice, “dB” often stands for “dB SPL”.

Because the decibel scale is logarithmic, a three-decibel increase in sound level already represents a doubling of [sound] intensity. For example, a normal conversation may be about 65 dB and someone shouting can typically be around 80dB. The difference is only 15 dB but the shouting is 30 times as intensive.

Please note that perception of loudness is not exactly the same as sound pressure level. To account for the fact that are particularly low and high-pitched sounds appear less loud to the human ear, noise is usually measured in A-weighted decibels (dB(A)). (Source: GreenFacts, based on EU-OSHA What is noise?  )


DG Health and Consumers

"The Health and Consumers DG (formally known as Health and Consumer Protection DG) is one of 36 Directorates-General (DGs) and specialised services which make up the European Commission."

The mission statement of the Health and Consumers DG is: "to promote a better quality of life by ensuring a high level of protection of consumers' health, safety and economic interests as well as of public health"

"This overall goal is addressed through legislative and non-legislative actions in three inter-related policy areas: 1. Consumer policy (...), 2. Public Health (...), 3. Food safety, animal health, animal welfare and plant health (...)". (Source: DG Health and Consumers website  )


The ear consists of the outer, middle, and inner ear. It plays a role in hearing, balance, and spatial orientation.

The outer ear collects sound. It includes the auricle, the auditory canal, and the external surface of the eardrum, which is a membrane separating the outer and middle ear.

The middle ear is the cavity behind the eardrum. In response to sound waves, the eardrum vibrates. The vibration is passed on to small bones (hammer, anvil, and stirrup) that amplify and transmit the vibrations to the inner ear.

The inner ear includes the vestibule and the cochlea. The vestibule is the organ that contributes to balance and spatial orientation. The cochlea is the hearing organ. It contains specialised sensory cells called hair cells. When the “hairs” are moved as a result of sound vibrations, these cells translate this mechanical stimulation into an electrical signal that is carried to the brain by the auditory nerve. (Source: GreenFacts, based on the National Institute for Health Glossary   )


Epidemiological studies

Studies on human populations, which attempt to link human health effects (e.g. cancer) to a cause (e.g. exposure to a specific chemical). (Source: GreenFacts)


European Commission

"The European Commission (EC) embodies and upholds the general interest of the [European] Union and is the driving force in the Union's institutional system. Its four main roles are to propose legislation to Parliament and the Council, to administer and implement Community policies, to enforce Community law (jointly with the Court of Justice) and to negotiate international agreements, mainly those relating to trade and cooperation."

The Commission's staff is organised into 36 Directorates-General (DGs) and specialised services, such as the Environment DG and the Research DG. (Source: EC website  )

Frequency (in the context of sound)

Frequency is the measurement of the number of times that a repeated event occurs per unit of time.

The frequency of wave-like patterns including sound, electromagnetic waves (such as radio or light), electrical signals, or other waves, expresses the number of cycles of the repetitive waveform per second.

In SI units, the result is measured in Hertz (Hz), named after the German physicist, Heinrich Rudolf Hertz. 1 Hz means one cycle (or wave) per second.

Frequency has an inverse relationship to the concept of wavelength (the distance between two peaks) such that the frequency is equal to the velocity divided by the wavelength. (Source: GreenFacts)



The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein. (Source: NHGRI Talking Glossary of Genetic Terms  )

Hearing loss

Hearing loss is a reduced ability to hear sounds in comparison to normal hearing. Hearing loss ranges from slight to profound.

Hearing loss can be caused by aging (age-induced hearing loss), illness or disease, by excessive exposure to high noise levels (noise-induced hearing loss) or by excessive exposure to loud sounds (sound-induced hearing loss). (Source: GreenFacts)

Hearing threshold

The hearing threshold is the sound level below which a person’s ear is unable to detect any sound. For adults, 0 dB is the reference level.

A threshold shift is an increase in the hearing threshold for a particular sound frequency. It means that the hearing sensitivity decreases and that it becomes harder for the listener to detect soft sounds. Threshold shifts can be temporary or permanent. (Source: GreenFacts, based on H&M Hearing, Glossary of audiology terms  )

Heavy metals

Metallic elements with high atomic weights, e.g. mercury, chromium, cadmium, arsenic, and lead.

They can damage living things at low concentrations and tend to accumulate in the food chain. (Source: US EPA Drinking Water Glossary  )


Inflammation is the reaction of living tissues to infection, irritation or other injury. (Source: GreenFacts)



MP3 is an audio file format, based on MPEG (Moving Picture Expert Group) technology. [This compression technology] creates very small files suitable for streaming or downloading over the Internet. (Source: University of Maryland University College, ADE Glossary  )


Nervous system

The nervous system is a complex, sophisticated system that regulates and coordinates body activities.

It is made up of:

  • the central nervous system, consisting of the brain and spinal cord, and
  • the peripheral nervous system which includes, the eyes, the ears, the sensory organs of taste and smell, as well as the sensory receptors located in the skin, joints, muscles, and other parts of the body.

In a narrow sense, noise can be considered as unwanted sound and refers to cases where the potentially affected person is not intentionally listening.

People who choose to listen to music or use personal music players can be exposed to loud sounds, which they do not consider as noise. An involuntary bystander may nevertheless be distracted and annoyed and may rightfully, call noise what is sound in his neighbour’s ears.

In a broader sense, noise is often used as a synonym for sound. (Source: GreenFacts, based on SCENIHR  "Potential health risks of exposure to noise from personal music players" )


Organic solvent

A chemical compound (usually liquid) containing carbon used to dissolve other substances such as paints, varnishes, grease, oil, etc. (Source: GreenFacts, based on Dow Product Safety Glossary  )

Personal music player

Portable audio equipment e.g.: CD- cassette- MP3- Player, mobile phones with [music playing] function. (Source: SCENIHR  "Potential health risks of exposure to noise from personal music players" )


A podcast is a digital recording of a radio broadcast or similar program , made available on the Internet for downloading to a personal music player. [By extension, includes] video as well as audio [files]. (Source: BBN Technologies, Glossary  )

Scientific Committee on Emerging and Newly Identified Health Risks

The Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) was set up in 2004 by the European Commission to provide the Commission with unambiguous scientific advice on the safety of a series of issues requiring a comprehensive assessment of the risks, such as new technologies, medical devices, etc.

The SCENIHR advice is intended to enable risk managers to take the adequate and required actions in order to guarantee consumer safety or public health.

The SCENIHR addresses questions concerning emerging or newly-identified risks and on broad, complex or multi-disciplinary issues requiring a comprehensive assessment of risks to consumer safety or public health and related issues not covered by other Community risk- assessment bodies.

The Scientific Committee on Emerging and Newly Identified Health Risks is composed of a maximum of 13 members, but for any specific question may enlist the support of up to six associated members selected on the basis of their expertise. There is also a reserve list made up of candidates found suitable for a position in a Scientific Committee but not appointed. The members of the SCENIHR are appointed on the basis of their skills and experience in the fields in question, and consistent with this a geographical distribution that reflects the diversity of scientific problems and approaches in the European Union (EU). The experts' term of office is three years and is renewable for a maximum of three consecutive times. In agreement with the Commission, the Scientific Committees may turn to specialised external experts.

The SCENIHR complies with the principles of independence, transparency and confidentiality. The members therefore make a declaration of commitment to act in the public interest and a declaration of interests; requests for opinions, agendas, minutes and opinions are published; work and publications are done with regard to the need for commercial confidentiality. (Source: SCENIHR pages  )

Sensory cells

Sensory cells are cells which detect information (such as sounds, light, touch, smell, taste, and temperature) through receptors on their surface. This information travels through nerves from the sensory cells to the brain. (Source: GreenFacts)


Sound is caused by vibrations and carries energy as a wave through all media – air, water, walls, windows etc. – but not through vacuum. In most situations sound is a complex sum of many signals from different sources which may interfere with each other. Like all waves, a particular sound can be described by a combination of individual frequencies which together form a pattern called the spectrum of the sound waves.

When sound waves reach the ear or measuring instrument the resulting change of pressure can be measured. Sound intensity is usually expressed in decibels of sound pressure level (dB SPL). (Source: GreenFacts, based on SCENIHR   "Potential health risks of exposure to noise from personal music players" )


Tinnitus is a condition in which a person hears a ringing, buzzing or hissing sound which is caused by the hearing system itself and not by any external sources.

Tinnitus can be temporary or persistent and is relatively widespread. It is often associated with hearing impairment, ageing or exposure to loud sounds, and generally involves the part of the nervous system that deals with hearing. (Source: GreenFacts, based on SCENIHR   "Potential health risks of exposure to noise from personal music players" )


Vitamins are a group of organic micronutrients that are required by the body for healthy growth, development and immune system functioning.

Certain vitamins are produced by the body but most vitamins are obtained from food or from manufactured dietary supplements. (Source: GreenFacts)


Vulnerability (in health science)

The likelihood of being unusually severely affected by a substance either as a result of susceptibility to the effects of these substances or as a result of a greater than average [exposure]. (Source: WHO Europe  Answers to follow-up questions from CAFE )

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