Huh! I had no idea either. Here ya go - just press that little speaker lol.
https://www.google.ca/search?q=petrichor+pronunciation&source=hp&ei=aiy7Ypu3Msu9tQbvzpCADA&iflsig=AJiK0e8AAAAAYrs6elP-YAbkymCFSD_JyP2nOosVapvn&oq=petrichor&gs_lcp=Cgdnd3Mtd2l6EAEYAjILCAAQgAQQsQMQgwEyCAgAEIAEELEDMgUIABCABDIFCAAQgAQyBQgAEIAEMgUIABCABDIFCAAQgAQyBQgAEIAEMgUIABCABDIFCAAQgAQ6DgguEIAEELEDEMcBEKMCOhEILhCABBCxAxCDARDHARCjAjoOCC4QgAQQsQMQgwEQ1AI6CAguEIAEELEDOggIABCABBDJAzoFCAAQkgM6FAguEIAEELEDEIMBEMcBEK8BENQCOhEILhCABBCxAxCDARDHARCvAToICAAQsQMQgwE6CwguEIAEELEDEIMBOggILhCABBDUAjoFCC4QgARQAFiMEmDYI2gAcAB4AIABkAGIAfIHkgEDMS44mAEAoAEB&sclient=gws-wiz
Got it!