Andreas Pavel

Andreas Pavel is a German-Brazilian cultural producer and media designer who is generally credited with the invention of personal stereo. [1] [2].

Born in Brandenburg, Germany, Pavel was the son of a German industrialist and vice-president of the Federation of German in Industries (BDI). When he completed six years of age, his family moved to São Paulo, where his father took a managing position at Brazil's main industrial conglomerate, the Matarazzo Industries.

Having studied philosophy and social sciences at the Free University of Berlin, Pavel returned to Brazil in 1967 and started his professional career as head of programming of the newly founded public broadcasting station, TV Cultura. 1970 he took up editorial planning at Abril Cultural, where he edited partwork encyclopaedias for nationwide newsstand distribution, most notably the philosophical source collection "Great Thinkers" and a reference series of "Brazilian Popular Music".

From 1968 onward Pavel lived in an arch-shaped house designed for his mother, the artist Ninca Bordano, by the architect Ronaldo Duschenes. The place became well-known for its legendary quality as a sound reproduction environment. Pavel was acquainted to some important personalities of the time, poets, musicians, philosophers, architects, social scientists, etc. who came regularly to the intellectual debates and music evenings at his house. It was in that effervescent environment of sound, culture, and politics, at a time of military dictatorship in Brazil, that Pavel developed his concept of a personal hifi-stereo listening system, in February 1972.

In the mid-1970s Pavel moved to New York and later Milan, where he established Mediadream Communications Research with the Italian photographer Alfonso Galasso and the Australian tv producer Jeremy Fabinyi and went on experimenting with sound, image, multimedia environments, produced some of the first video clips, and also cooperated with jazz musician Sun Ra and his Intergalactic Research Arkestra. In June 1977 he wrote the blueprint for a personal hifi-stereo system, "The Coming Audio Revolution", and designed a high end modular version of it, the Stereobelt, which is now part of the Museum for Italian Design, in Milan.

Over the next few years Pavel tried to interest companies like Yamaha, Uher, Beyer, B&O, and Brionvega in manufacturing his personal hifi-stereo system. In March 1977, Pavel filed the first patent application on the new medium in Italy [3] followed by further applications in the United States, Germany, the United Kingdom, and Japan.

Personal Stereo did not come up as an incremental improvement; it was a quantum leap when high fidelity music reproduction suddenly became available anywhere, at any time. This was described by Italian critic and media theorist Enrico Ghezzi as an "anthropological mutation" that transformed people's ordinary life into some kind of cinema, and as a "secret theatre" by French semiotician Shuhei Hosokawa (The Walkman Effect, in: Popular Music 1984/4).

Before Pavel was ready to introduce the new system with the Italian manufacturer Brionvega, Sony took the global market by launching the Walkman in July 1979. After a personal contact between Pavel and Sony President Akio Morita, the company started legal talks in 1980 regarding a possible agreement on royalty fees. But it only agreed to such pay royalties, on some early models, after it lost its challenge to Pavel's German patent. At the same time Sony redesigned the Walkman to eliminate two much-praised features: the double headphone sockets, which allowed two listeners to enjoy the same mobile hifi experience, and the non-recording microphone and mixing circuit that improved communication and increased situational awareness, both of which had been disclosed and claimed in all of Pavel's patent applications [e.g. German Patent Application DE 2813000].

In 1989, Pavel started infringement proceedings against Sony in the UK. Four years later, the British patent was invalidated by a British judge at the request of Sony's lawyers, even though the same judge confirmed its infringement of Pavel's patent claims, the contrary trends at the time, the fact that Sony testified that its first internal discussion of personal stereo happened within two weeks of Pavel's patent publication (October 5th, 1978) - in spite its technical feasibility much before that date -, the reactions of astonishment first inside the company and on a worldwide basis after it was introduced, and its unprecedented commercial success, producing one of the steep sales curve in the history of consumer electronics.

Pavel was left with a cost order of $3.6 million to cover the litigation expenses of Sony and Toshiba, who had joined it in opposing Pavel's patent claims. In 1999, Pavel threatened Sony with further legal suits in every country in which he had patented his invention. The corporation agreed to resume talks with Pavel and a settlement was finally reached in 2003. The agreement led Pavel to switch off a website that he had created to report on the litigation (

The exact settlement fee is a closely guarded secret, but European press accounts said that Pavel received a cash settlement for damages in excess of $10,000,000 and is now also receiving royalties on some Walkman sales.[4] The settlement also includes a clause which will prevent Pavel from bringing future lawsuits based on the same set of patents and patent applications. The settlement grants Pavel the recognition from Sony that he was the original inventor of personal stereo, as exemplified by and introduced with Sony's Walkman. It was achieved after the death of Akio Morita, the founder of Sony who was sometimes credited as the creator of the Walkman, even though this was in contrast with many other accounts produced by Sony, including the one it presented in court.

25 years later, Apple's digital MP3 stereo player, the iPod, took the place of Sony's Walkman. Both products represented an epochal breakthrough for their respective manufacturers. Today the digital stereo player is an integral part of every smartphone. Pavel reportedly had considered asking Apple and other manufacturers of portable digital music players for royalties. However, in December 2005 he said he did not intend to do so, not wishing to spend any more time in lawsuits and negotiations.

In recent years Pavel has focused on a multi-media sensory extension kit (the "Dreamkit"), large-scale stereo loudspeakers, and has worked in a new kind of immersive telephony. He has also created the largest existing database of recorded Brazilian music and produced the last great master of Brazilian "choro" music, the late flutist Altamiro Carrilho ( as documented in "A Fala da Flauta”, a 4-DVD-set).

Andreas Pavel
EducationFree University of Berlin
Engineering career
Significant designStereobelt (proto-Walkman)


  1. ^ Rohter, Larry (December 17, 2005). "Unlikely trendsetter made earphones a way of life". The New York Times.
  2. ^ Kerbusk, Klaus-Peter (May 24, 2004). "In die Tasche gesteckt". Der Spiegel.
  3. ^ Dumout, Estelle (June 4, 2004). "Sony pays millions to inventor in Walkman dispute". CNET News.
  4. ^ Rohter, Larry (December 16, 2005). "Portable stereo's creator got his due, eventually". International Herald Tribune.

Further reading

  • Percezione senza più limiti – parla il padre di Walkman e iPod (Il Sole 24 Ore 21/09/2006)
  • Jacques Attali, Une brève Histoire de l’Avenir (Paris, 2006)
  • Jack Challoner, ed, 1001 Inventions that changed the world (London, 2009)
  • Revista Veja, Especial “Os Pioneiros” (São Paulo 31/08/2011)
  • Eric Chaline, 50 Machines that changed the course of History (London, 2012)
  • Rainer Schönhammer, Der Walkman: Eine phänomenologische Untersuchung (München, 1988)

Astraltune, also known as the Astraltune Stereopack, was a portable/personal audio player created by Roy Bowers that appeared on the market in Reno Nevada on September 1, 1975.


Brazil (Portuguese: Brasil Portuguese pronunciation: [bɾaˈziw]), officially the Federative Republic of Brazil (Portuguese: República Federativa do Brasil, listen ), is the largest country in both South America and Latin America. At 8.5 million square kilometers (3.2 million square miles) and with over 208 million people, Brazil is the world's fifth-largest country by area and the fifth most populous. The capital is Brasília, and the most populated city is São Paulo. The federation is composed of the union of the 26 states, the Federal District, and the 5,570 municipalities. It is the largest country to have Portuguese as an official language and the only one in the Americas; it is also one of the most multicultural and ethnically diverse nations, due to over a century of mass immigration from around the world.Bounded by the Atlantic Ocean on the east, Brazil has a coastline of 7,491 kilometers (4,655 mi). It borders all other South American countries except Ecuador and Chile and covers 47.3% of the continent's land area. Its Amazon River basin includes a vast tropical forest, home to diverse wildlife, a variety of ecological systems, and extensive natural resources spanning numerous protected habitats. This unique environmental heritage makes Brazil one of 17 megadiverse countries, and is the subject of significant global interest and debate regarding deforestation and environmental protection.

Brazil was inhabited by numerous tribal nations prior to the landing in 1500 of explorer Pedro Álvares Cabral, who claimed the area for the Portuguese Empire. Brazil remained a Portuguese colony until 1808, when the capital of the empire was transferred from Lisbon to Rio de Janeiro. In 1815, the colony was elevated to the rank of kingdom upon the formation of the United Kingdom of Portugal, Brazil and the Algarves. Independence was achieved in 1822 with the creation of the Empire of Brazil, a unitary state governed under a constitutional monarchy and a parliamentary system. The ratification of the first constitution in 1824 led to the formation of a bicameral legislature, now called the National Congress. The country became a presidential republic in 1889 following a military coup d'état. An authoritarian military junta came to power in 1964 and ruled until 1985, after which civilian governance resumed. Brazil's current constitution, formulated in 1988, defines it as a democratic federal republic. Due to its rich culture and history, the country ranks thirteenth in the world by number of UNESCO World Heritage Sites.Brazil is considered an advanced emerging economy. It has the eighth largest GDP in the world by both nominal and PPP measures. It is one of the world's major breadbaskets, being the largest producer of coffee for the last 150 years. It is classified as an upper-middle income economy by the World Bank and a newly industrialized country, with the largest share of global wealth in Latin America. Brazil is a regional power and sometimes considered a great or a middle power in international affairs. On account of its international recognition and influence, the country is subsequently classified as an emerging power and a potential superpower by several analysts. Brazil is a founding member of the United Nations, the G20, BRICS, Union of South American Nations, Mercosul, Organization of American States, Organization of Ibero-American States and the Community of Portuguese Language Countries.

List of inventors

This is a list of notable inventors.

Organ procurement

Organ procurement (previously called organ harvesting) is a surgical procedure that removes organs or tissues for reuse, typically for organ transplantation. It is heavily regulated by United Network for Organ Sharing (UNOS) to prevent unethical allocation of organs. There are over 110,000 patients on the national waiting list for organ transplantation and in 2016, only about 33,000 organ transplants were performed. Due to the lack of organ availability, about 20 patients die each day on the waiting list for organs. Organ transplantation and allocation is mired in ethical debate because of this limited availability of organs for transplant. In the United States in 2016, there were 19,057 kidney transplants, 7,841 liver transplants, 3,191 heart transplants, and 2,327 lung transplants performed.

Organ transplantation

Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transported from a donor site to another location. Organs and/or tissues that are transplanted within the same person's body are called autografts. Transplants that are recently performed between two subjects of the same species are called allografts. Allografts can either be from a living or cadaveric source.

Organs that have been successfully transplanted include the heart, kidneys, liver, lungs, pancreas, intestine, and thymus. Tissues include bones, tendons (both referred to as musculoskeletal grafts), corneae, skin, heart valves, nerves and veins. Worldwide, the kidneys are the most commonly transplanted organs, followed by the liver and then the heart. Corneae and musculoskeletal grafts are the most commonly transplanted tissues; these outnumber organ transplants by more than tenfold.

Organ donors may be living, brain dead, or dead via circulatory death. Tissue may be recovered from donors who die of circulatory death, as well as of brain death – up to 24 hours past the cessation of heartbeat. Unlike organs, most tissues (with the exception of corneas) can be preserved and stored for up to five years, meaning they can be "banked". Transplantation raises a number of bioethical issues, including the definition of death, when and how consent should be given for an organ to be transplanted, and payment for organs for transplantation. Other ethical issues include transplantation tourism (medical tourism) and more broadly the socio-economic context in which organ procurement or transplantation may occur. A particular problem is organ trafficking. There is also the ethical issue of not holding out false hope to patients.Transplantation medicine is one of the most challenging and complex areas of modern medicine. Some of the key areas for medical management are the problems of transplant rejection, during which the body has an immune response to the transplanted organ, possibly leading to transplant failure and the need to immediately remove the organ from the recipient. When possible, transplant rejection can be reduced through serotyping to determine the most appropriate donor-recipient match and through the use of immunosuppressant drugs.

Personal stereo

A personal stereo is a portable audio player using an audiocassette player, battery power and in some cases an AM/FM radio. This allows the user to listen to music through headphones while walking, jogging or relaxing. Personal stereos typically have a belt clip or a shoulder strap so a user can attach the device to a belt or wear it over his or her shoulder. Some personal stereos came with a separate battery case.

The first personal stereo was the Stereobelt invented and patented by West German-Brazilian inventor Andreas Pavel in 1977. Pavel attempted to commercialise this invention but failed to do so.The first commercial personal stereo was the Sony Walkman released in 1979, created by Akio Morita, Masaru Ibuka (the co-founders of Sony) and Kozo Ohsone. It became a popular and widely imitated consumer item in the 1980s. In the 1990s, portable CD players became the most popular personal stereos. In the 2000s, digital players like the iPod became the dominant personal stereos. During this period, smartphones (advanced cell phones) like the iPhone also became popular music listening devices.


The Stereobelt was the first portable personal stereo audio cassette player. It was invented by the German-Brazilian Andreas Pavel. The Stereobelt was the ancestor of the Walkman and later personal audio devices such as the iPod.

A former television executive and book editor, Pavel invented the Stereobelt to "add a soundtrack to real life" by allowing the user to play high-fidelity music through headphones while participating in daily activities.

The initial test of the device took place in February 1972 in St. Moritz, Switzerland, when Pavel pushed the play button to start the song "Push Push" by Herbie Mann and Duane Allman. Pavel experienced a "floating" sensation as he listened to the music and watched the mountain snow fall, realizing that his new device could provide "the means to multiply the aesthetic potential of any situation."Pavel approached electronics manufacturers such as ITT, Grundig, Yamaha and Philips with his invention, but the companies felt that no one would ever want to wear headphones in public for listening to music.

Frustrated with his lack of progress, and learning that it was important to protect his idea, Pavel finally filed a patent for the Stereobelt in Italy in 1977, followed by patent applications in the U.S., Germany, the United Kingdom and Japan by the end of 1978.

Sony began selling the arguably similar Walkman personal stereo in 1979. In negotiations that began in 1980 and ended in 1986, Sony agreed to pay Pavel limited royalties for the sales of certain Walkman models sold in his home country of Germany only (about 150.000 deutsche Mark, almost 1% of Sonys Walkman profit in Germany).

A second round of legal battles between Pavel and Sony that began in 1989 in Great Britain ended when the case was dismissed in 1996, leaving Pavel to pay more than $3 million in court costs.

Finally in 2003, with Pavel threatening to file infringement lawsuits in the other territories where he holds patents, Sony agreed to settle out of court, which led to both parties signing a contract with confidential content in 2004. The settlement was reported to be a cash payment of over $10,000,000 and ongoing royalties of the sale of certain Walkman models.


Walkman is a series of portable media players and some Sony Ericsson mobile phones manufactured by Sony. The original Walkman, released in 1979, was a portable cassette player that changed listening habits by allowing people to listen to music on the move. It was devised by Sony cofounder Masaru Ibuka, who felt Sony's existing portable player was too unwieldy and expensive. A prototype was built from a modified Sony Pressman, a compact tape recorder designed for journalists.

The Walkman was followed by a series of international releases; as overseas sales companies objected to the Japanese-English name, it was sold under several names, including Soundabout in the United States, Freestyle in Sweden, and Stowaway in the UK. Eventually "Walkman" caught on globally and Sony used the name worldwide. Sony continues to use the "Walkman" brand for most of its portable audio devices.

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