What is the usual bandwidth of an amateur radio single-sideband signal?

Human voice communication can be effectively understood within an audio frequency range of about 300 Hz to 3000 Hz. In a single-sideband (SSB) transmitter, audio filters restrict the voice baseband to approximately this range in order to conserve spectrum space. Because SSB transmits only one sideband and suppresses the carrier, the final radio frequency bandwidth perfectly matches this filtered audio bandwidth. Therefore, a standard amateur SSB signal occupies between 2 kHz and 3 kHz of spectrum, making it highly efficient compared to standard AM.