Humans may well benefit from a soothing voice of encouragement during stressful situations, but scientists found no evidence in a study that horses derive a similar benefit.
The researchers from the United States, Italy and Germany found no evidence to show that soothing vocal cues enhanced the ability of a horse to learn a frightening task. Their findings have been published in the Journal of Veterinary Behavior.
Michigan State University researcher Camie Heleski and her colleagues said it was frequently asserted that horses had an inherent understanding of harsh voice cues that would be used as reprimands, with soothing voice cues able to be used as positive reinforcement or a calming influence.
“If horses are unable to understand this difference while their handlers assume they can, it may potentially lead to unfair or inappropriate training,” the researchers said.
A total of 107 horses from two different horse facilities in the US and seven different horse facilities in Europe were used in the study.
They were randomly assigned into either the soothing voice treatment group, which had 58 horses, or the harsh voice treatment group, which had 49 horses.
The learning task, which was standardized across all the locations, involved horses of various breeds and ages learning to cross a tarpaulin on the ground.
Horses in the soothing voice group were given the words “good horse” in a soft, soothing manner whenever they made forward progress toward the tarpaulin.
The harsh voice group were given the words “quit it” in a loud, harsh manner whenever horses made forward progress toward the tarpaulin.
The average loudness of the soothing voice group was 51.2 decibels, compared to 61.7 decibels for the harsh voice group..
The horses were considered to have failed the task if they took more than 10 minutes to cross the tarpaulin for the first time.
Later analysis showed the risk of failing the task was not different between the groups (22.4 percent of those in the soothing voice group failed, compared to 24.5 percent in the harsh voice group).
For horses who successfully crossed the tarpaulin, the researchers found that the total time to achieve agreed calmness criteria – crossing with little or no obvious anxiety – did not differ between each voice group.
There was no difference between the average heart rate of horses who crossed and those who failed. There was also no difference between the average heart-rate of horses between the two groups.
“In the context of this study, soothing vocal cues did not enhance horses’ ability to perform a novel, potentially frightening task,” they concluded.
C. Heleski, C. Wickens, M. Minero, E. DallaCosta, C. Wu, E. Czeszak, and U. Köenig von Borstel.
Do soothing vocal cues enhance horses’ ability to learn a frightening task?
The abstract can be read here.