Santa Barbara-based inbound call technology firm Invoca has added Salesforce.com to its investor roster and released a new voice intelligence technology to help its customers decode incoming calls.

Invoca’s software lets marketers generate unique phone numbers for campaigns and then route and track the calls and sales that result. The company has raised more than $30.8 million to date, with the most recent round a $20 million infusion from Accel Partners.

Invoca did not disclose the amount of Salesforce.com’s investment but said it was part of the Series C round that brought aboard Accel. Last fall, Invoca re-branded itself and added Brett Queener, executive vice president at Salesforce.com, to its board of directors.

“The investment from Salesforce.com will accelerate Invoca’s growth and product innovation so that marketers will no longer have to guess the important details about the billions of inbound phone calls from their best customers and prospects,” Invoca CEO Jason Spievak said a news release.

The new product is called Invoca Signal. It listens to inbound sales calls and automates each action based on scoring techniques and metrics derived from a company’s sales process. The end goal is to give marketing executives a clear picture of the process from call to purchase, similar to how online customers’ actions are followed from click to purchase to determine the return on their marketing spend.

Invoca said the new signal technology has been put into use at “one of the world’s largest retailers.”