Yes, any iPod touch 2nd generation and above can run VoiceJam.
The 4th generation iPod touch and possibly all future models all have built-in microphones and speakers, meaning no extra accessories are required to use VoiceJam. For older models without built in microphones, you will need to attach a 3rd party headset or headphones that include a microphone, or any 3rd party device that provides audio input recording simultaneously with sound output.
For your convenience, below you will find a list of compatible products. More can be found by searing the web for headphones designed for music production, interactive gaming, or voice over IP communications.
TC-Helicon does not endorse nor guarantee the quality or compatibility of any of these 3rd party products or companies: