Unipolar, bipolar or sinusoidal transmitters may leave the transmitter in any of various states at the end of one pulse. Undesired acoustic energy may be generated to change states prior to beginning another transmit sequence or pulse. For example, phase inversion for tissue harmonic imaging is performed where two sequential pulses are transmitted with different phases. The first waveform starts at a low state and ends at the low state of a unipolar transmitter. The next waveform starts at the high state. Transmit apodization or spectrum control techniques may require a pattern of waveform starting states different than a current state. Acoustic disruption due to a change of state of the transmitter between transmissions for imaging is minimized. The acoustic disruption is minimized by focusing the acoustic energy generated by the switch of states away from a scan line or scan lines being used for imaging or by defocusing the energy within the scan region generated due to the switching of states of the transmitter between acquisition cycles.