India's call centre industry has grown rapidly in the past decade, but recent research suggests it's no longer the world's biggest. Some British and American companies are moving operations back home, so what's the future for Indian phone bashers?

In a classroom above a bus station in Mumbai, a group of students is being given a language lesson.

"B-U-T is pronounced as 'but', however P-U-T is pronounced 'poot', [like foot] not 'putt'," explains teacher Stephen Rosario, as he coaches the class in how to enunciate English words.

The students, who are mostly college graduates in their 20s, are doing vocal exercises: "Cake, Lake, Take," they chant in unison, trying to perfect their accents, as Mr Rosario waves his hand in encouragement.

The lessons here at the Let's Talk academy are designed to teach young Indians to speak with a "neutral-sounding accent" to train them for work at a call centre.

The sound of an Indian accent at the end of the customer service line has been frustrating for many consumers in English-speaking countries who have had difficulties understanding or being understood.

And some customers evidently just don't like accented speech even when they can understand it.

It can often lead to irate and heated conversations, which workers at the Indian end are also trained to deal with.

"First and foremost, I tell the students when the customer is angry do not interrupt... just listen.

"I teach them to maintain a soft demeanour - because when a customer is aggressive you mustn't retaliate," says Mr Rosario.

How to get a 'neutral-sounding accent' "We give them mouth and jaw exercises which correspond to vowels and consonants," says Aakash Kadim, owner of Let's Talk academies

Mr Kadim says in order for workers to get rid of their regional Indian accents, they use sounds to build words

"For instance, an Indian might pronounce water, 'Vatter' so we teach them how to say 'awe' sounds so they pronounce the word w 'awe' ter"

They also teach various idioms, like "eye-opener" "bear the brunt" and "pull your socks up" to familiarise them with British English

In the past decade, the Indian call centre industry has boomed, and along with it complaints from customers. Now dissatisfaction with accents has prompted some British and American companies to move operations out of India.

Spanish-owned bank Santander recently moved all its English-language call centre work back to the UK. Earlier in the year, insurance group Aviva moved some operations back to Norwich, while New Call Telecom recently relocated its customer service work from Mumbai to Burnley.

"Customers often find it difficult to communicate to someone sat out in India," says New Call Telecom's managing director Nigel Eastwood, who hopes to improve efficiency and call handling times as a result of the move.

New Call Telecom, and other companies that have made a similar decision, hope it will improve service, and be more cost-efficient. But some Indians are hurt by what they interpret as disdain for their accents.

'Abusive words'

At his desk in a busy call centre in Mumbai, Valerian (whose call centre name is "Andy") is talking to a customer back in England. Valerian has spent the past 18 months wearing a headset and a microphone to talk to people in their kitchens and living rooms in the UK.

"Sometimes we're just calling to help people but... they abuse us and that's really upsetting because we're just here to do our job," he says.

Image caption Some firms have moved operations back home

"I've had some abusive words thrown at me, but it's fine," says Michael, another worker at the centre. "I'm used to it now."

But the call centres are facing other pressures too. A job in a call centre in India is no longer as prized as it used to be, says Aakash Kadim, the owner of the Let's Talk academies.

"A call centre today is no longer a prestigious career here in India. Initially you wanted to get into the call centre industry to make quick money," he says. Over time, young graduates have become more aware of the downsides, such as night shifts and lack of career progression.

Mr Kadim says the number of people hired into jobs through his academy has fallen drastically in recent years - he now recruits hundreds of students annually rather than tens of thousands.

The rising cost of living is also pushing up the price of running a call centre in Indian cities, including Mumbai and Delhi, where rising interest rates and inflation are having an impact on property prices, which is giving South East Asian countries an edge.

India now faces stiff competition from the Philippines, according to recent research from IBM. The study for the Contact Center Association of the Philippines estimates that 350,000 Filipinos work in call centres, compared with 330,000 Indians.

But India's growing economy could provide other opportunities, says Akil Mahimwala, who owns Altius Customer Services, a call centre operation in Mumbai. With more Indians now owning cars, credit cards and mobile phones there is a growing domestic market that has a need for call centres.

"Indian companies have taken up a lot of the slack from companies that stopped outsourcing working from the US and the UK.

"They have now started doing a lot of domestic work. Customer service has become a lot more important to companies over here and they don't mind paying for it," he says.

Falling property prices and the recession were other reasons New Call Telecom decided to pack up operations from India to England.

But the Indian economy is still growing fast, and is likely to keep its call centres in work for years to come.