When Johann Philipp Reis used his telephone to transmit the phrase "the horse does not eat cucumber salad", 150 years ago, the German scientist could never have guessed this sentence was about to revolutionise communications.

Alexander Graham Bell (1847 - 1922) makes the first telephone call from
New York to Chicago in 1892. Bell invented the telephone sixteen years
earlier in 1876. Pic/ Getty Images

Reis presented his invention in a lecture titled, Concerning the reproduction of sounds over any distance by means of galvanic electricity, to the Physical Society of Frankfurt on October 26, 1861. The 27-year-old chose the unusual phrase about horses and cucumbers so that a listener could not guess the meaning of the sentence without hearing every single word.

Reis had developed an artificial ear out of wood for his physics class, using a piece of sausage casing stretched on fine platinum strips to replicate the eardrum. Although he achieved brief renown, Reis failed to make the big breakthrough. His telephone could only transmit sound and the person at the receiving end was unable to answer immediately.

Reis died in January 1874 at the age of 40 from tuberculosis before he could further develop his invention.
It was only when Alexander Graham Bell brought the first commercial telephone -- which was held to the ear and mouth -- to the market in the 1870s that the telecommunication revolution really began.

Bell and his assistant Thomas Watson experimented with acoustic telegraphy. The inventor believed that multiple metal reeds tuned to different frequencies could convert currents back into sound. When Watson accidentally plucked one of the reeds, Bell noticed that only one reed was necessary.

This realisation led to the "gallows" sound-powered telephone, which was able to transmit indistinct, voice-like sounds, but not clear speech. Bell was awarded the first US patent for the telephone in 1876 and soon the appliances were operated almost exclusively by women as higher-pitched voices were easier to understand.

In 1877-78, Thomas Edison invented and developed the carbon microphone used in all telephones -- along with the Bell receiver -- for another century. As Edison noted, Reis was "the first inventor" of a telephone, Bell was the first person "to publicly exhibit a telephone for transmission of articulate speech" while "the first practical commercial telephone for transmission of articulate speech was invented by myself."

The telephone was initially greeted with scepticism. When Berlin's first telephone directory was published in 1881, it was described as the "book of fools." Telephones were also considered luxury goods, but this didn't stop their relentless spread across the globe.

Telephone operators are long a thing of the past since the advent of automatic exchanges, but even with all the technological advances, using telephones remained expensive until the end of the last century.

Digital technology and the opening of markets, combined with the meteoric rise of the mobile phone, has finally seen telephones become an everyday fixture of most people's lives in the developed world.

Fixed-line telephones are increasingly being replaced by mobile phones. Industry association BITkom estimates the telephone industry, including mobile phone manufacturers and network providers, to be worth around 2 trillion dollars.

According to market research company Gartner, 1.6 billion mobile phones were sold last year, of which 20 per cent were smart phones with Internet access.