Audio recordings of language programs—streaming—have an advantage over print or academic classes because hearing is how humans learn to speak. That is how we learned our native tongues, and how we effectively learn second languages. As babies, we listened to our parents speaking. In our hard-wired desire to communicate, we learned our native language by imitating them. According to linguists, babies begin by distinguishing basic syllables, and around 3 months, start to babble, making simple sounds (“ba-ba-ba” or “ma-ma-ma”). They also imitate the tonal changes of their parents’ language. By sixmonths, they can distinguish the sounds of their native language fromthose of foreign languages and begin to practice its sounds, intonations, and rhythms.Most children by the age of 1 year can say a few simple words, even if they aren’t clear on theirmeanings. At 18months, most children have a speaking vocabulary of eight to ten words. By 2, they begin forming simple sentences. And then language fluency begins to soar. In the early 1900s, European linguists proposed that language learning would be better if it were conducted in the target language. In this approach—called the Direct Method (or Natural Method)—all directions, explanations, and definitions are given in the language being taught. In a French class, French and only French is spoken or read. All grammar is learned inductively. While this method most closely imitates the way we learn our first language, it is difficult to teach and can be frustrating and discouraging to learners. Most audio-based language learning programs combine both native and target languages into talking phrasebooks.

Tracy Hogg who died from cancer on November 25 2004 aged 44, built a career as an expert in child-care and was nicknamed "the baby whisperer" for her ability to placate unruly infants. Although British, she made her name in the eclectic state of California, where she was hired as a maternity nurse and adviser by many Hollywood stars, among them Jodie Foster, Cindy Crawford, Jamie Lee Curtis and Calista Flockhart; even Arnold Schwarzenegger is said to have sought her counsel. The Yorkshire-born Dr Dolittle of the nursery always addressed her employers as "love" or "duck". It was a Hollywood producer who first referred to her as "the baby whisperer" - a reference to the book and film The Horse Whisperer, about a racehorse trainer with an uncanny ability to communicate with animals. She once said: "I've looked after so many thousands of babies, I can understand their language. And I teach new parents to understand their baby too. I also get babies on a routine, so that after three weeks they're sleeping through the night." Her fee for three weeks as a maternity nurse was more than ,000. If there was nothing particularly original about Tracy Hogg's approach to baby care, she had, according to her web site, "an uncanny ability to understand what babies need by listening to their cries and tuning in to their body language." This ability had probably been sharpened by earlier work she had undertaken with disabled children, who often lack verbal communication skills. Tracy Hogg was born to a large dairy-farming family near Doncaster, South Yorkshire, in August 1960. As a child she enjoyed accompanying her grandfather as he made his rounds at a local mental hospital, where he was head nurse. She attended the Doncaster School of Nursing. specialising in children with severe mental and physical disabilities. She underwent further training at Great Ormond Street, at the Children's Hospital in Leeds, and also did a stint with the World Health Organisation in India. At St Catherine's Hospital, Doncaster, she looked after children with learning difficulties. In 1992 she moved to America with her second husband, a car dealer, leaving her two young daughters from her first marriage in the care of their grandmother. This led some to question her parenting abilities, but Tracy Hogg wanted her children to continue their education in England, and the girls joined her during the holidays. Soon after arriving in Los Angeles, she was asked to help out a family with a new-born baby. The mother was Marilu Henner, who starred in the television sitcom Taxi. After that, reports of Tracy Hogg's skills spread by word of mouth. She went on to open a baby supplies store and set up an internet site, describing herself as "a British-trained nurse, lactation educator, and newborn consultant". In addition to working with individual clients, she organised classes for parents and trained child-care workers. In 1997 she produced an audio-tape for breast-feeding mothers which was designed to induce relaxation and reduce anxiety.