Hi Nikolay,
Thanks for the post. Your question would best be answered by the Plantronics folks over at Sounding Board. --> Welcome | Plantronics Sounding Board Community
The forums here at the Plantronics Developer Connection are mostly to answer developer questions about integration and building apps using the Spokes SDK. Any and all headset questions can be answered at Sounding Board community.
Sorry to give you the run around, but would you be able to post your question to the forums found at Welcome | Plantronics Sounding Board Community?
Thanks so much!
Greg.