There is not a particular frequency that universally places cats to sleep. https://www.youtube.com/watch?v=s-TH3xAV5xo , like people, have individual preferences and reactions to different frequencies and sounds. However, there are certain frequencies which are generally associated with relaxation and sleep, and a few cats might discover them calming. For example:
Purring Sounds: The frequency of a cat's purr is generally between 25 and a hundred and fifty Hertz. Hearing different cats purr, or even enjoying recordings of purring, may be soothing for some cats and help them relax.
Low Frequencies: Sounds at decrease frequencies, sometimes called bass sounds, can create a sense of calm and relaxation. Frequencies between 25 and one hundred fifty Hertz, which embrace the purring vary, are generally thought of low frequencies.
White Noise: White noise, which encompasses a wide range of frequencies, can masks different sounds within the setting and create a constant background noise that some cats discover stress-free. It's not a few specific frequency however the constant and non-disturbing sound.

Music and Ambient Sounds: Some ambient music tracks or nature sounds used for leisure are designed with a combination of frequencies, together with decrease ones, to create a calming ambiance.
It's necessary to note that while sure frequencies may be associated with relaxation, particular person cats can react differently. Some cats would possibly find low-frequency sounds calming, whereas others may choose higher frequencies. Additionally, the overall surroundings, the cat's mood, and its particular persona all play a role in the way it responds to totally different frequencies.
If you are trying to create a calming environment in your cat, think about experimenting with different types of music, ambient sounds, or white noise machines, and observe your cat's conduct to see what it responds to positively. Always keep the quantity at a stage that's comfortable on your cat, as loud or sudden noises may cause stress quite than leisure..