U.S. researchers say they dissected what compassionate speech sounds like to create a behavioral taxonomy -- classification -- to guide medical training.

Dr. Ronald Epstein, a professor and director of the University of Rochester's Center for Communication and Disparities Research in New York state, said the team listened to physicians talk to patients and broke down the dialogue and studied the context.

"Good to see you. I'm sorry. It sounds like you've had a tough, tough week" -- spoken by a doctor to a cancer patient -- is an example of compassionate behavior, Epstein, the research team's senior investigator, said.

"In healthcare, we believe in being compassionate, but the reality is that many of us have a preference for technical and biomedical issues over establishing emotional ties," Epstein said in a statement.

The research team recruited 23 oncologists from a variety of private and hospital-based oncology clinics in the Rochester area. The doctors and their stage III or stage IV cancer patients volunteered to be recorded during routine visits. Researchers then analyzed the 49 audio-recorded encounters that took place between November 2011 and June 2012, and looked for key observable markers of compassion.

In contrast to empathy, compassion involves a deeper and more active imagination of the patient's condition. An important part of this study, therefore, was to identify examples of the three main elements of compassion: recognition of suffering, emotional resonance, and movement towards addressing suffering, Epstein said.

Emotional resonance, or a sense of sharing and connection, was illustrated by this dialogue: Patient: "I should just get a room here." Oncologist: "Oh, I hope you don't really feel like you're spending that much time here."

The researchers also observed non-verbal communication, such as pauses or sighs at appropriate times, as well as speech features and voice quality -- tone, pitch, loudness -- and other metaphorical language that conveyed certain attitudes and meaning.

Epstein said the team found compassion unfolded over time and during the process, physicians must challenge themselves to stay with a difficult discussion, which opens the door for the patient to admit uncertainty and grieve the loss of normalcy in life.

"It became apparent that compassion was not a quality of a single utterance but rather is made up of presence and engagement that suffuses an entire conversation," the study said.

The study was published in the journal Health Expectations.