Published: Apr 24, 2014 5:52 PM EDT

When you're dealing with an emergency, every second counts.

A new study reveals using a cell phone indoors to call 911 could cost the caller precious moments.

Charlotte County's emergency dispatch center receives tens of thousands of 911 calls every year, the majority of which come from cell phones.  Most calls are also placed from inside buildings.

Enhanced dispatch administrator Laurene Anderson has decades of dispatch experience, and knows that when dealing with an emergency, caller's can't always tell the operator where they are.

"They may be hiding for some reason. They don't want somebody to hear them," Anderson said.

A survey of 911 dispatchers from the Washington, D.C.-based Find Me 911 Coalition reveals how difficult it is to poinpoint a location when a caller is using a mobile phone inside.

"Yyou get a general vicinity of their X-Y coordinates," Andersona said.  "However, in a lot of cases, it's not going to tell you what floor they're on."

According to the survey, 82 percent of dispatchers do not have confidence in location data provided by wireless phone carriers.

FCC guidelines only require location accuracy of up to 150 meters for at least 95 percent of GPS-enabled devices.  

In February, the FCC proposed new requirements for mobile carriers to automatically give 911 dispatchers more accurate location information.  Carriers have two years to comply with those requirements.