Hello!Thank you for your question. I am Shefin and I look forward to helping you with your issue today.
Make sure that you have properly inserted the microphone cable (if you are using a desktop with no mic built in).
If you are using a Laptop, make sure that you are selecting the correct Microphone in Audio settings (in Skype).
If the issue persists, try installing the latest audio driver for your computer. Please let me know the model number, so that I can help you install the driver.
S H E F I N