Audio-conferencing may be classified among which of the following types of communication?

Audio-conferencing is classified as two-sided verbal communication, since participants speak and reply through words.

All parties can talk back over the audio link, making the exchange interactive and two-way.

It is not one-sided verbal, because listeners are not silent receivers but active speakers.

It is not one-sided non-verbal, since the medium carries spoken words rather than only gestures.

It is not two-sided non-verbal, because sound and speech, not visible body cues, form the channel.

Voice-based back-and-forth over distance defines audio-conferencing as two-sided verbal.