How is the "push to talk" feature different in the SpeechMike Air III as compared to the SpeechMike Air II?

Question: How is the playback volume controlled? The playback volume is controlled during playback using the [+] (plus) and [-] (minus) buttons on the VOL rocker switch on the right side of the DS-2200. Pressing [+] increases the playback volume. Pressing [-] reduces the playback volume.Verification Source: Olympus Website