THE PERSON I ADMIRE

Loudspeakers use both electric and mechanical principles to convert an electrical signal from a radio, television set or electric musical instrument into sound. For a loudspeaker to produce sound, the signal from the radio, television set, or electric musical instrument needs to be connected to an electronic amplifier.
Loudspeakers are usually built by using stiff paper cone, a coil of thin copper wire, and a circular magnet. The cone, copper wire, and magnet are usually mounted in a rectangle-shaped wood cabinet. The coil of copper wire moves back and forth when an electrical signal is passed through it. The coil of copper wire and the magnet cause the rigid paper cone to vibrate and reproduce sounds. loudspeaker (or "speaker", or in the early days of radio "loud-speaker") is an electroacoustic transducer that produces sound in response to an electrical audio signalinput. In other words, speakers convert electrical signals into audible signals. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful.
The most popular speaker used today is the dynamic speaker. The dynamic speaker operates on the same basic principle as a dynamic microphone. When an ac current (i.e., electrical audio signal input) is applied through the voice coil that surrounds a magnet (or that is surrounded by a permanent magnet), the coil is forced back and forth due to Faraday’s law, which causes the paper cone attached to the coil to respond with a back-and-forth motion that creates sound waves. Where high fidelity reproduction of sound is required, multiple loudspeakers may be used, each reproducing a part of the audible frequency range. Miniature loudspeakers are found in devices such as radio and TV receivers, and many forms of music players. Larger loudspeaker systems are used for music, sound reinforcement in theatres and concerts, and in public address systems.
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Essentially, hearing aids are electronic devices that pick up sound waves with microphones, which then process that sound through an amplifier, then send the processed sound into the eardrum with a speaker (receiver).

• The simplicity and complexity with which this is achieved depends on the type of instrument that is used.

• For instance, the newest, digital hearing aids contain very sophisticated and powerful processors and are able to sample the sound environment, manipulate the wanted and unwanted sounds all in times measured in milliseconds. The end result is clearer sound, with minimal distortion.

• Simpler hearing aids, while still effective, do not process sound as effectively as digital instruments.

• It’s important to note that hearing improvement with any instrument depends on the type and degree of hearing loss, proper diagnostic testing and the fitting of the hearing aid. No hearing aid can restore normal hearing and not everyone benefits equally, but they can provide a significant improvement to those who have sustained hearing loss. DIFFERENT TYPES OF HEARING AIDS: Hearing aids come in five main types:

1. Behind-The-Ear (BTE) – This hearing device is housed in a curved shell that sits behind each ear and delivers sound through a clear tube normally via a custom made earmould.

2. In-The-Ear (ITE) – Easy to operate, even for users with poor dexterity, ITE devices are housed in a custom-made shell that fits comfortably inside each ear

3. In-The-Canal (ITC) – Barely visible, ITC devices are housed in a custom-made shell that fits comfortably in each ear canal, delivering sound directly to the ear. Though small, ITC devices are easy to operate, even for users with poor dexterity.

4. Completely-In-Canal (CIC) – Fitted inside each ear canal, CIC devices are all but invisible from the outside. These miniature instruments are both powerful and cosmetically appealing, but due to their small size they may sacrifice some features such as multiple program options and manual volume controls.

5. Open-Ear-Fitting (OEF) – A radical advance in hearing aid design, these ultra-small ear canal devices use sophisticated sound processing technology to set a new standard in aesthetics and comfort. These are replacing many of the above styles due to their high performance and superb comfort as well as cosmetic acceptability.

A hearing aid is an electroacoustic device which is designed to amplify sound for the wearer, usually with the aim of making speech more intelligible, and to correct impaired hearing as measured by audiometry. In the United States, Hearing aids are consideredmedical devices and are regulated by the Food and Drug Administration (FDA). Ordinary small audio amplifiers or other plain sound reinforcing systems cannot be sold as "hearing aids".
Earlier devices, known as ear trumpets or ear horns,[1][2] were passive funnel-likeamplification cones designed to gather sound energy and direct it into the ear canal. Similar devices include the bone anchored hearing aid, and cochlear implant.

Nelson Rolihlahla Mandela (/mænˈdɛlə/;[4] Xhosa pronunciation: [xoˈliːɬaɬa manˈdeːla]; 18 July 1918 – 5 December 2013) was a South African anti-apartheid revolutionary,politician, and philanthropist who served as President of South Africa from 1994 to 1999. He was South Africa's first black chief executive, and the first elected in a fully representative democratic election. His government focused on dismantling the legacy ofapartheid through tackling institutionalised racism, poverty and inequality, and fostering racial reconciliation. Politically an African nationalist and democratic socialist, he served as President of the African National Congress (ANC) from 1991 to 1997. Internationally, Mandela was Secretary General of the Non-Aligned Movement from 1998 to 1999.
A Xhosa born to the Thembu royal family, Mandela attended the Fort Hare University and the University of Witwatersrand, where he studied law. Living in Johannesburg, he became involved in anti-colonial politics, joining the ANC and becoming a founding member of itsYouth League. After the South African National Party came to power in 1948, he rose to prominence in the ANC's 1952 Defiance Campaign, was appointed superintendent of the organisation's Transvaal chapter and presided over the 1955 Congress of the People. Working as a lawyer, he was repeatedly arrested for seditious activities and, with the ANC leadership, was unsuccessfully prosecuted in the Treason Trial from 1956 to 1961. Influenced by Marxism, he secretly joined the South African Communist Party (SACP) and sat on its Central Committee. Although initially committed to non-violent protest, in association with the SACP he co-founded the militant Umkhonto we Sizwe (MK) in 1961, leading a sabotage campaign against the apartheid government. In 1962, he was arrested, convicted of conspiracy to overthrow the state, and sentenced to life imprisonment in theRivonia Trial.
Mandela served over 27 years in prison, initially on Robben Island, and later in Pollsmoor Prison and Victor Verster Prison. An international campaign lobbied for his release. He was released in 1990, during a time of escalating civil strife. Mandela joined negotiations with President F. W. de Klerk to abolish apartheid and establish multiracial elections in 1994, in which he led the ANC to victory and became South Africa's first black president. He published his autobiography in 1995. During his tenure in the Government of National Unity he invited several other political parties to join the cabinet. As agreed to during thenegotiations to end apartheid in South Africa, he promulgated a new constitution. He also created the Truth and Reconciliation Commission to investigate past human rightsabuses. While continuing the former government's liberal economic policy, his administration also introduced measures to encourage land reform, combat poverty, and expand healthcare services. Internationally, he acted as mediator between Libya and the United Kingdom in the Pan Am Flight 103 bombing trial, and oversaw military intervention in Lesotho. He declined to run for a second term, and was succeeded by his deputy,Thabo Mbeki. Mandela became an elder statesman, focusing on charitable work in combating poverty and HIV/AIDS through the Nelson Mandela Foundation.
Mandela was a controversial figure for much of his life. Denounced as a communistterrorist by critics,[5][6] he nevertheless gained international acclaim for his activism, having received more than 250 honours, including the 1993 Nobel Peace Prize, the USPresidential Medal of Freedom, the Soviet Order of Lenin and the Bharat Ratna. He is held in deep respect within South Africa, where he is often referred to by his Xhosa clan name,Madiba, or as Tata ("Father"); he is often described as "the father of the nation".

ollowing the news of the passing of Nelson Mandela at the age of 95, millions of people in South Africa and around the world have been in mourning. His image, writes Rick Stengel, TIME’s former managing editor and collaborator with Mandela on Mandela’s 1993 autobiography, Long Walk to Freedom, “has become a kind of fairy tale: he is the last noble man, a figure of heroic achievement.” The many tributes pouring in from world leaders are testament to those achievements. But it is the memories shared over the years by some of the people who knew him and those who only had brief encounters that best illustrate the kind of man Mandela was.
ANC’s, South Africa’s governing political party, Deputy Secretary-General Jessie Duarte, who was his personal assistant between 1990-94:
“He always made his own bed, no matter where we traveled. I remember we were in Shanghai, in a very fancy hotel, and the Chinese hospitality requires that the person who cleans your room and provides you with your food, does exactly that. If you do it for yourself, it could even be regarded as an insult.
So in Shanghai I tried to say to him, ‘Please don’t make your own bed, because there’s this custom here.’ And he said, ‘Call them, bring them to me.’
So I did. I asked the hotel manager to bring the ladies who would be cleaning the room, so that he could explain why he himself has to make his own bed, and that they not feel insulted. He didn’t ever want to hurt people’s feelings. He never really cared about what great big people think of him, but he did care about what small people thought of him.”
South African photographer, Steve Bloom, whose father, Harry Bloom was a political activist:
During the 1950s my parents, who were anti-apartheid activists, knew Nelson Mandela. I remember the story he told them about the occasion he saw a white woman standing next to her broken car in Johannesburg. He approached her and offered to help. After fiddling with the engine he fixed the car. Thankful for his help, she offered to pay him sixpence.
“Oh no, that’s not necessary,” he said, “I am only too happy to help.”
“But why else would you, a black man, have done that if you did not want money?” she asked quizzically.
“Because you were stranded at the side of the road,” he replied.
Neville Alexander, a political activist who spent ten years imprisoned on Robben Island alongside Mandela, describes his first meeting with him:
“I was impressed mainly by the warmth and the genuine interest, which was a feature that, subsequently I discovered, is very much part of the man and something which I also must admit now, I learned from him … to give your full attention to your interlocutor, and really take notice of what people are saying, listen to them carefully. In his case, there was a spontaneous, charismatic exuding of warmth. That’s probably the most important, most vivid memory I have of our first meeting.”
Wolfie Kodesh, who hid Mandela for nearly eight weeks in 1961 in his apartment in a white suburb of Johannesburg:
“…We had a discussion and an argument about who is going to sleep where. I had a tiny flat … and I had a bed and I had a camp stretcher in a cupboard. So when I brought out the camp stretcher, I said to him, ‘Well, I’ll sleep on the camp stretcher. You sleep on the bed because you are six foot something, I am five foot something. So the stretcher is just right for me.’ No, he wasn’t going to have that. He hadn’t come there to put me out, and we had a bit of a talk about that and … it was arranged, and I would sleep on the bed.”
Rick Stengel, who spent almost two years with Mandela working on his autobiography, Long Walk to Freedom:
“In 1994, during the presidential-election campaign, Mandela got on a tiny propeller plane to fly down to the killing fields of Natal and give a speech to his Zulu supporters. I agreed to meet him at the airport, where we would continue our work after his speech. When the plane was 20 minutes from landing, one of its engines failed. Some on the plane began to panic. The only thing that calmed them was looking at Mandela, who quietly read his newspaper as if he were a commuter on his morning train to the office. The airport prepared for an emergency landing, and the pilot managed to land the plane safely. When Mandela and I got in the backseat of his bulletproof BMW that would take us to the rally, he turned to me and said, “Man, I was terrified up there!”"

I admire a lot of people people but the person i admire the most is