This paper presents a systematic comparative study on the high-frequency noise of permanent magnet motors driven by two-level and three-level inverters. First, the voltage harmonics under space vector pulse width modulation (SVPWM) are analyzed through theoretical derivation, identifying the dominant voltage harmonic components and their variation with the modulation index. Second, based on the frequency and phase sequence of current harmonics, the resulting radial forces of spatial order 0 and spatial order 2p are derived. Finally, simultaneous current and noise measurements are conducted on a test bench to compare the PWM current harmonics and sideband noise of the two inverter types over a wide speed range. The results indicate that for noise near the first carrier frequency, the three-level inverter does not provide advantages across the entire speed range. When the modulation index falls below 0.5, its noise performance is worse than that of the two-level inverter. For noise near the second carrier frequency, the three-level inverter consistently exhibits lower noise than the two-level inverter across all speed ranges.