Specifically, the study found that how couples talk to each other about their emotions can affect the way partners feel in the relationship, according to the press release.
"What you say is not the only thing that matters; it's very important how you say it," University of Utah doctoral student Md Nasir said in the release. "Our study confirms that it holds for a couple's relationship as well."
Researchers reviewed more than 100 conversations from couples who were going through marriage therapy for two years and tracked their marital statuses for three additional years, according to Science Daily.
The researchers created a new computer algorithm that measured how a partner's tone affected the relationship. The algorithm took the therapy recordings and broke them "into acoustic features using speech-processing techniques such as pitch, intensity, 'jitter' and 'shimmer,' along with tracking warbles in the voice that can indicate moments of high emotion," according to the press release.
Through the algorithm, the researchers found that certain tones and sounds were associated with the changing state of a couple's relationship.
"It's not just about studying your emotions," USC's Shrikanth Narayanan said in the release. "It's about studying the impact of what your partner says on your emotions."
The researchers said this was one of the first studies to show how specific tones and sounds reflect a couple's relationship status.
Researchers have long advised couples to be wary of how they speak with their spouse when confronting them with an argument or when communicating in general.
For example, Mitch Temple of Focus on the Family suggests that people often make mistakes when they approach their spouse by showing disrespect toward them, losing their control because of anger or blaming their spouse for relationship issues.
The best way to approach your spouse is by first finding the right time when he or she isn't stressed out or too busy, Temple explained. The approach should also be non-confrontational and topics should be brought up in a "non-threatening way," Focus on the Family explained.
"If your communication pattern has digressed to the point that when you bring up this topic, your spouse becomes defensive and 'blows up,' you may consider writing him or her a letter to be read when you are not present," according to Focus on the Family. "This gives your spouse time to think about what was said and respond without all the emotions."
Similarly, Good Therapy, a website that helps people find therapists and therapeutic advice, listed tone of voice as one of the most important parts of building a strong marriage. Susan Heitler, Ph.D., wrote for Good Therapy that couples often have an easier time communicating when they show positive emotions.
"Positivity in tone of voice, actions such as hugs and smiles, and in words, makes communication flow more smoothly and affection grow more amply," Heitler wrote. "Positivity enables partners to feel more relaxed with each other, which also helps them to feel flexible and eager to be responsive to each other's concerns."
Heitler also suggests couples stay calm in moments when there are marital issues to keep negative emotions away.
"Every negative emotional tone is like rust on the car — it's corrosive, not helpful," she wrote. "And relationships feel positive to the extent that the partners can discuss all their differences in a calm mode without powering over each other via emotional escalations."