Here's how:
* Common Noun: When "voice" refers to the sound produced by the vocal cords, it's a common noun.
* Example: "The singer had a beautiful voice."
* Abstract Noun: When "voice" refers to a more abstract concept like opinion, expression, or style, it's an abstract noun.
* Example: "The author gave a voice to the voiceless."
Let me know if you'd like more examples!