Dogs can recognise their owners by voice alone when neither vision nor smell is there to guide them, according to a new study that sheds more light on how animals may identify humans based on speech.
The research, published in the journal Animal Cognition, suggests canines identify their owners just based on their voice alone by making use of some of the same voice properties such as pitch and timbre that humans do.
In the study, scientists from the Eötvös Loránd University (ELTE), Hungary invited 28 owner-dog pairs to play hide-and-seek in the lab, and the canines had to find their owner behind one of two hiding places while a stranger hid behind the other one.
They then played the owner’s voice from the owner’s hiding place, and a stranger’s voice from the other hiding place, both reading out recipes in a neutral tone.
Scientists assessed if the dogs could choose from a distance and find their owners.
Over the course of the experiment, through multiple rounds, researchers paired the owners’ voices with 14 different strangers’ voices – some more similar to the owner’s voice, some more different.
The study found that the dogs could find their owner in 82 per cent of the cases, suggesting that the dogs could significantly identify their owner’s voices.
In order to ensure that the dogs were not guided by their sense of smell towards their owners, in the last two rounds, researchers played the owner’s voice from where the stranger hid.
Scientists found that in these rounds the dogs still went for the voice, indicating they did not use their nose in this task.
“Dogs’ high choosing success rate, their ability to discriminate their owner’s voice from a variety of control voices, and the fact that dogs’ choices were not confounded by either olfactory cues or speaker order indicate that dogs can reliably use identity cues carried by speech,” scientists wrote in the study.
“This is the first demonstration that dogs can tell apart their owner’s voice from many others. The study also shows that dogs make use of some, but only some of the same voice properties as humans do to recognise who is talking,” study co-author Andics Attila, said in a statement.
The research also suggests dogs use the same voice properties such as pitch and timber to identify people.
“People mostly make use of three properties: pitch (higher or lower), noisiness (cleaner or harsher), and timbre (brighter or darker) to differentiate others. Dogs may make use of the same voice properties or different ones. If two voices differ in a property that matters for dogs, decisions should be easier,” Anna Gábor, lead author of the study, explained.
Scientists say if the owner’s and the stranger’s voice differed more in pitch and noisiness, it helped dogs recognise their owner’s voice.
However timbre and other sound properties did not help the dogs differentiate between the owners and strangers, they added.
