What determines the PEP-to-average power ratio of an unprocessed single-sideband phone signal?

In an unprocessed single-sideband (SSB) transmitter, there is no constant carrier. The RF output is a direct translation of the baseband audio frequencies into radio frequencies. Therefore, when you are not speaking, there is no power output. Because the RF envelope perfectly matches the audio envelope, the ratio of Peak Envelope Power (PEP) to average power is entirely dictated by the unique peaks, pauses, and inflections of the operator's voice. These are collectively known as 'speech characteristics.' Other factors like amplifier gain, carrier suppression, or the specific pitch (frequency) of the voice do not change the fundamental peak-to-average ratio of the waveform itself. Only altering the audio envelope—either naturally through speech patterns or artificially with a speech processor—will change this mathematical ratio.