Hearing voices when no one is there can be a symptom of mental illness, yet a study of the phenomenon found nearly half the people who heard voices said their hallucinations were mostly friendly or helpful.
Furthermore, some participants in the Auckland University study considered their voices a blessing - although others thought them a curse.
Hearing voices tends to be more accepted in some indigenous cultures than in modern Western society - but it still finds a place, even at top levels.
Retired Australian athlete Herb Elliott, winner of the 1500m gold at the 1960 Rome Olympics, has written of the voice in his head that told him halfway through that race: "Herb, you're buggered."
He ignored the negative comment, won and became an adviser on the psychology of winning to a new generation of Australian Olympic athletes.
For the study, psychologist intern and post-graduate student Vanessa Beavan gathered answers from 154 voice-hearers by questionnaire and interviewed 50 of them for her PhD thesis. Her findings provide an insight into a phenomenon estimated to be experienced by 5 per cent to 10 per cent of people.
She is using her research to help promote World Hearing Voices Day on September 14.
"Hearing voices is more complex than suggested by the psychiatric model of voices as a symptom of severe mental illness," Ms Beavan said. "Voice-hearers ... reported a diverse range of experiences and explanatory models and most had never been diagnosed with a psychiatric disorder."
While 54 per cent had been in contact with mental health services, only 22 per cent said it was for reasons "at least somewhat related to their voice experiences".
Positive voice content included hearing advice, encouraging and comforting words, and giggling.
On the darker side, negative content could be crying, criticism or commands to hurt themselves or others.
More than half identified a single event, mostly negative, happening shortly before they first heard a voice, yet, over time, participants' emotional reactions to their voices became more commonly positive than negative.
Voices of deceased people were the most common; others included parts of the self, gods and aliens.
People attributed their voices to causes like brain dysfunction, drugs, trauma and spiritual entities.
Ms Beavan said people needed to develop their own coping strategies, but techniques like "selective listening" could be effective.
Many participants wanted voice-hearing to be considered normal, to reduce the stigma they experienced.
Waitemata District Health Board psychiatrist Dr Wayne Miles said not all hallucinations were associated with mental illness.
Many experienced them when waking or falling asleep, or if someone close had recently died. About a fifth of people suffering from schizophrenia heard voices.
"We are more likely to see people in a distressed state because the voices are in some ways negative," he said.
"The worst are the ones that constantly tell you you're terrible, you should kill yourself.
It's likely they aren't that common."
VOICE-OVER
* 154 people who hear voices took part in the Auckland University study.
* The voices were mostly friendly or helpful for 48 per cent, mostly negative or unhelpful for 25 per cent, neutral for 15 per cent and varied greatly for the rest.
* 54 per cent had been in contact with mental health services.
* Around 25 per cent heard voices talking or arguing with each other.