Loudness in different rooms versus headphone reproduction: Is there a mismatch even after careful equalization?
* Presenting author
Even though our expectation is that sound reproduced by loudspeakers in a room should exert the same perceived loudness if reproduced by individually equalized headphones, findings from the literature (e.g., Munson 1952, Fastl et al. 1985) indicate a mismatch: Equal sound pressure levels at the eardrum do not guarantee an equal perceived loudness. The aim of this study is to characterize this mismatch as a function of room acoustics and headphone type. Subjects balanced the perceived loudness between presentations of an identical stimulus from a loudspeaker and a headphone for three different rooms (anechoic, office room, reverberation chamber) and two different headphones (Sennheiser HD650 and Beyerdynamic DT770). Additionally, a comprehensive acoustic characterization of the headphones with different measurement devices was conducted.The results confirm a loudness mismatch with a weak effect of the room type, indicating that room acoustics (and perhaps the individual expectation and the subjective spatial impression of the room) biases our loudness judgement. This is important for sound reproduction systems in rooms and the limited fidelity of room simulations even with carefully individualized headphones. The consequences of our findings and necessary steps to pin down the origin of the observed mismatch will be discussed.