You can create your own "auditory sigil" from an affirmation or statement of will. You take or create a phrase expressing what you want. For example: "I am safe and everything is okay." Write it out and delete all of the repeated letters. So this sentence will become:
IAMSAFEANDEVERYTHINGISOKAY and then
IAMSFENDVRYTHGOK and then rearrange the letters into a word or phrase that sounds good to you. This could become
SMO'KYF GRIVNA DEHT (or any other combination of the letters) and chant this like a mantra when you feel an onset of anxiety.
You could do this process with a whole prayer or passage, song, whatever, that you like.
But, some well-known ones are the OM mantra, Metta mantra, Great Compassion mantra. Or recite the chakra seed mantras.