Re accent and voice training, dependant on your specific outcomes, some tools from Neuro Linguistic Programming (NLP) can be extermely powerful – after all, if you wish to change your accent, voice or personal impact, you need to change your thinking patterns that lead to your current accent or impact. We have and continue to use lots of NLP tools in our call centre training events – perhaps it could be worthwhile searching NLP trainers in your country with specialist knowledge of call centres and telephone based communication.