Oral-binaural room impulse responses measured on singers in various halls

Oral-binaural room impulse response (OBRIR) refers to the acoustic transfer function from mouth to ears measured in a room, which is useful especially for the evaluation of the stage acoustics from the performers' perspective, where it can also be employed for auralization. OBRIRs have typically been measured on head and torso simulators, whereas the measurement on human was considered to be difficult, for example, for the limited spectrum of the human-generated source sound and for the variance of the data in the course of a long measurement time. Recently, a method was proposed to effectively measure the OBRIRs on singers where singing major scales within 1~2 minutes was found to be sufficient to produce usable transfer functions. In the current study, OBRIRs were measured by using this method on volunteer singers in a few performance spaces with varying size. As expected, the OBRIRs differed between singers, where the impulse responses after the arrival of the direct sound heavily depended on the acoustic properties of the room. The singer's position and orientation on the stage and the type of vowel pronounced for the measurement were also shown to modulate the OBRIRs.