Making sounds during sexual arousal and sexual activity is widespread among primates and humans. These include sighs, moans, strong expirations and inspirations, increased breathing rate and occasionally, at orgasm, screams of ecstasy. Many of these sounds are highly exciting to men and women, and act as strong reinforcers of sexual arousal, creating a powerful positive feedback effect.[14] Thus, copulatory vocalisations are likely to serve mutual sexual stimulation for mating partners.[15]