The voicemail-to-text service Spinvox has applied¹ for two patents which describe the service as being operated by humans, the BBC has learned.

BBC了解到，语音信箱-文本转换服务商Spinvox已经申请两项专利，称此项服务为人工操作。

A Spinvox customer claims to have been contacted by a call centre

Spinvox has previously² claimed that state-of-the-art speech recognition technology is the basis of its service.

However, its patent applications claim the approach is accurate precisely³ because it employs human operators.

Spinvox's head of social media said that the patents were just two among many for which the firm had applied.

The BBC has also learned that an employee of a call centre in Pakistan tagged his own appeal onto a Spinvox message sent to a US customer, claiming that workers there had not been paid.

Spinvox has always maintained that humans only play a minor⁴ role in converting voice messages into text.

Both patent applications were lodged⁵ in the United States in the name of Daniel Doulton, the company's co-founder. The first, which was filed originally in 2004, describes a "method of providing voicemails to a wireless⁶ information device" .

It says an operator "intelligently transcribes⁷（抄写，译写） the actual message from the original voice message", and concludes that "because human operators are used instead of machine transcription, voicemails are converted accurately⁸, intelligently, appropriately and succinctly⁹（简明地） into text messages."

The second application, which appears to be dated July 2nd 2009, describes a similar system, but goes into more detail .

It says "the task of constructing voice recognition software that can reliably and accurately recognise natural speech...remains¹⁰ a daunting¹¹（令人畏惧的） one." But it says Spinvox's invention challenges the orthodoxy（正统说法，正教） by using human operators.

When queried¹²（疑问，质问） about one of these patents by a commentator¹³（注释者） on the firm's blog, Spinvox's head of social media James Whatley said it was just one among many.

"Spinvox has an entire family of over 70 patents currently residing at international patent offices and many of them have different purposes for their application/submission," he said.

"The one you quote sits firmly under the umbrella of 'the strategic patent'. Generic¹⁴ patents help us build different combinations - i.e.: Humans interacting with machines - to prevent any other companies doing similar things in the long term."

'Real trouble'

Meanwhile Jason Lovell, a Spinvox customer from Virginia in the US, said he received an email from the service this March that included an audio file of a voicemail message for him.

The text read: "We are employees of Spinvox. Since voicemail to text message service has started by Spinvox we are converting your messages here in Pakistan."

It invited him to ring a number in Pakistan and concluded "You can confirm please we are in real trouble. Please for God sake."

Mr Lovell told BBC News that a friend rang the number on his behalf and was told the workers at the call centre were angry because they had not been paid for two months.

The BBC has asked Spinvox to comment on the patent issue and on Mr Lovell's story.