This review paper discusses the advancements in Head-Related Impulse Response measurement methods. HRIR (Head-Related Impulse Response) measurement methods, often referred to as HRTF (Head-Related Transfer Function) measurement methods, have undergone significant changes over the last few decades [1]. A frequently employed method is the Discrete stop-and-go method [1][2]. It involves changing the location of a single speaker, used as the sound source, and recording the impulse response at each location. [2]. Since the measurement is for 1 location of the sound source at a time, using the discrete stop-and-go method is time-consuming [1]. Hence improvements are required to enhance the efficiency of the measurement process such as using more sound sources (speakers) [1][3]. A typical HRTF measurement is usually conducted in an anechoic chamber to achieve a simulated free-field measurement condition without room reverberation. It measures the transfer function between the source and the ears to perceive localisation cues such as inter-aural time differences (ITDs), inter-aural level differences (ILDs), as well as monaural spectral cues [4]. Newer techniques such as the Multiple Exponential Sweep Method (MESM) and the reciprocal method offer alternatives. These methods enhance measurement efficiency and address challenges like inter-reflections and low-frequency response [5][6]. Individualised HRTF measurement techniques can be categorised into acoustical measurement, anthropometric data, and perceptual feedback [7]. Interpolation methods and non-anechoic environment measurements have expanded the practical application and feasibility of HRTF measurements [8][9][10][7].
