In the medical fields, ultrasound detection is often performed with piezoelectric arrays that enable one to simultaneously map the acoustic fields at several positions. In this work, we develop a novel method for transforming a single-element ultrasound detector into an effective detection array by spatially filtering the incoming acoustic fields using a binary acoustic mask coded with cyclic Hadamard patterns. By scanning the mask in front of the detector, we obtain a multiplexed measurement dataset from which a map of the acoustic field is analytically constructed. We experimentally demonstrate our method by transforming a single-element ultrasound detector into 1D arrays with up to 59 elements.