Simply speak into your phone or computer while recording a greeting with your business phone service. If you need to create your own audio file, the voice memo app on your phone should do fine.
Hello, you have reached Dr. A. We are busy assisting patient on the another line. Please, leave your details, including the case number if applicable, name, and phone number. For a medical emergency, hang up and call 911.

In Australian English it’s pronounced with the vowel /a:/ like in ‘part’. Problems arise when people use the /ʌ/ vowel (like in ‘up’) instead of /æ/ or /a:/. If you do this is will sound like the worst swear word in English. Many non-native speakers often pronounce the vowel /æ/ more like /ʌ/ because they don’t have a vowel like /æ/ in their first language. Many speakers of European languages will do this (Spanish speakers and Italian speakers) and also speakers of Japanese and Korean. This problem with /æ/ also means that if you say the word ‘back’ in your voicemail greeting sample, you are likely to pronounce it more like ‘buck’. remember to pronounce word endings in English. Check you aren’t dropping any endings off or mispronouncing them.
6. Vacation Voicemail Greetings. Hey, this is [your name] at [X company]. I am actually on a break at the moment, on the other side of the world! Please direct all phone calls to [alternate contact name] at [phone number] and emails to [X email address].