Parametric array loudspeakers, as a new type of directional sound source, not only have broad application prospects in noise control, personal communication, acoustic detection, and material measurement, but can also be used for intelligent sound field control. In active noise control, using parametric array loudspeakers as secondary sound sources can not only reduce secondary path acoustic feedback, but also reduce the impact of secondary sound sources on non-control areas in the sound field. According to the principle of sound wave cancellation interference, if the secondary sound source produces a sound wave with equal amplitude and opposite phase to the primary sound source, it will cancel each other out after superimposing with the original sound field in that area, thereby reducing noise. In the active noise control system, traditional omnidirectional loudspeakers are generally used as secondary sound sources, resulting in noise reduction in the control area, but noise will increase in other areas. When the control area is a certain direction or specific local space, the omnidirectional traditional loudspeakers cannot meet the requirements well. However, a parametric array loudspeaker with high directivity can be used as a new type of audio source for active noise control systems. The on-site measurement of the sound absorption coefficient of materials is an important topic in the field of architectural acoustics. The existing reflection method using ordinary loudspeakers has high requirements for material size and testing environment, and due to the limitations of spherical waves, it needs to use sound field models and iterative approximation algorithms to approximate, which can easily generate errors. Parametric array loudspeakers, due to the directional sound frequency generated by nonlinear effects, have plane wave characteristics in the near field, which can better meet the requirements of on-site measurement. However, there are still many practical problems that need to be analyzed and solved when applying parametric array loudspeakers to the measurement field. In the measurement of air acoustics, the measurement of the sound absorption coefficient has mainly relied on the impedance tube method and the reverberation chamber method for many years. This chapter reviews the current main applications of parametric array loudspeakers, and focuses on detailed explanations of its applications in active noise control in free space, pipeline active noise control, and field measurement coefficients.