Some 40 years after global cassette production began in earnest, sales are in terminal decline.

From its creation in the 1960s through to its peak of popularity in the 1980s, the cassette has been a part of music culture for 40 years.

But industry experts believe it does not have long left, at least in the West.

The cassette may have hissed, been prone to wow and flutter, and often ended its life chewed in a tape deck, but it ruled for four decades before MP3s and downloads.

However, the cassette's reign now seems to be over.

"Cassette albums have declined quite significantly since their peak in 1989 when they were selling 83 million units in the UK," Matt Phillips of the British Phonographic Industry (BPI) told BBC World Service's The Music Biz programme.

"Last year we saw that there were about 900,000 units sold. It's clear to see that cassette sales are dwindling fast."

Mix tape

Dutch electronics giant Philips perfected the design of the cassette in the 1960s.

It was designed to be a new form of portable entertainment, launched into a market dominated by vinyl LPs and reel-to-reel tape recorders.

Oddly, Philips did not charge royalties on their cassette patent, allowing numerous other companies to use their design for free. This ensured the quick acceptance of it as a new form of media.

It went on to accrue enormous worldwide sales. At its mid-80s peak, it sold 900 million units a year, 54% of total global music sales.

The music industry itself, however, remained concerned about cassettes, in particular the ability of people to record music on them.

They feared piracy, arguing that home taping was "killing music", a similar argument to the one occurring today over downloading.

One thing home taping allowed was the creation of the mix tape - a compilation of songs often put together as a present for a loved one. The process of creating the mix tape was immortalised by Nick Hornby in his novel High Fidelity.

New York music writer Joel Keller laments that personal computers have killed the mix tape star, and that the "drag and burn" method of creating compilation CDs is simply "less fun."

"I liked it when I sat in front of my stereo, my tape deck, with a big pile of CDs, deciding on the fly which songs to put in what order," he said.

"My play and record fingers got a little sore because I had to time it right. Listening to the song as it played, finding the levels - it seemed like more of a labour of love than it is it do CDs now."

Legacy

However, while cassettes are disappearing quickly from the music stores, they are clinging on in the UK in bookshops.

Having begun as a way of providing titles to the blind, a third of all audio books are still sold on cassette. An audio recording of a bestseller such as The Da Vinci code can sell between 60-70,000 copies in the UK alone.

"Audio tapes are like an old friend that doesn't go away," Pandora White of Orion audio books told The Music Biz.

"I think it's the accessibility of it. Where you stop and start is immediately where you left off, whereas CD can be a bit more tricky."

And outside of the music stores of the West, cassettes do continue to survive as a music format, in countries such as Afghanistan and India.

In some markets, performers record directly onto cassette.

Keith Joplin, a Director of Research at the International Federation of Phonographic Industries, said that Turkey still sells 88 million cassettes a year, India 80 million, and that cassettes account for 50% of sales in these countries. In Saudi Arabia, it is 70%.

However, he added that this is because the penetration of CD players "is not 100% in those markets."

With the US's largest magnetic tape factory ceasing production earlier this year, there are fears that even if cassettes are wanted in future, there will no longer be anything to wrap around the spools.

However, terms such as fast forward, rewind, record and pause, everyday words bequeathed to us from the tape era, ensure that in the English language at least, the legacy of the cassette will survive.