Want to let your loved one know how you really feel? You should try grunting sweet nothings into their ear. A new study has found that when it comes to emotions, sounds speak louder — and clearer — than words.

For the study, now published in the online journal Biological Psychology, a team of researchers from McGill University in Canada used an EEG (electroencephalogram) to measure the brain activity of 24 volunteers while they listened to a random mix of vocalizations associated with emotions, such as growls (anger), laughter (happiness), and sobbing (sadness), and nonsense words. They then measured how long it took for the participants to process each sound or word while they completed a separate task.

EEG results showed clear differences between how long it took the participants' brains to process the sounds and words — vocalizations were detected far more quickly than words. More specifically, vocalizations of happiness were generally processed faster than those of anger or sadness. Angry sounds and speech, however, left a longer impression on the brain than any other emotion. The participants' moods also affected how quickly and how strongly they responded to the cues. Individuals who were more anxious, for example, had a faster and more heightened response to emotional voices than their less anxious counterparts.

“People who tend to be anxious directed more attention to the meaning of the voices very early on,” lead researchers Dr. Mark Pell told Medical Daily in an email. “Possibly because many emotional voices can be sources of threat and high anxiety is linked to a bias for processing events that could be threatening.”

The researchers believe this heightened response to vocalizations may have evolutionary roots. Before the onset of language, ancient humans needed to decipher the emotional meaning behind utterances in order to socialize with their neighbors. Those who deciphered faster and more effectively had a better chance of surviving. This reasoning also explains why angry emotions leave such a lasting impression on the brain; in the past, this alerted humans to steer clear of danger.

“Vocalizations appear to have the advantage of conveying meaning in a more immediate way than speech," lead researcher Dr. Mark Pell said in a statement. "Our findings are consistent with studies of non-human primates, which suggest that vocalizations that are specific to a species are treated preferentially by the neural system over other sounds."

Because it was introduced to our species at a later date, language had less time to develop such a strong neurological response. Even though we now have language to better convey our emotions, Pell said, this study suggests we still shouldn't forget the importance of vocalizations.

“I hope that people will realize how important our voice is for communicating our emotions and attitudes” Pell told Medical Daily. “Emotions expressed non-linguistically are more basic and highly effective in communication.”

Source: MD Pell, K Rothermich, P Liu, S Paulmann, S Sethi, S Rigoulot. Preferential decoding of emotion from human non-linguistic vocalizations versus speech prosody. Biological Psychology. 2016