Rumbling, humming, booming – Perception of vehicle interior noise at low engine speeds

On the role of an introduction phase in experiments on the perception of vehicle interior noise

“…The other two sounds of the introduction phase were real recordings, one, where the magnitude of the sensation was high and one that did not elicit any of the three sensations. Details of the sounds are provided in [1]. The experiment of the present study without the introduction phase was essentially a replication of the main experiment of the FVV project, except for the introduction phase, which was replaced by a questionnaire, where the listeners were asked to explain the sensations and provide examples of sounds they associated with the sensations.…”

“…A problem with these sensations is that they are not well defined, even in the scientific literature, and are sometimes used interchangeably (see, e.g. [1], for an overview). Definitions that allow differentiating between the three sensations are provided in [7].…”

“…If a sound contains such an unmodulated low-frequency component and, in addition, higher-frequency components which are modulated at a rate that is similar to the frequency of the low-frequency component, the sound elicits the sensation of booming. Doleschal et al [1] used the definition of [7] to measure the impact of variations of parameters of interior noises of vehicles with a combustion engine running at low speeds on the magnitude of these sensations. Their listeners were nonexperts.…”

“…The latter category includes the sensations of humming, rumbling and booming which are commonly associated with sounds that contain low-frequency tonal components. In the context of vehicle interior sounds, these were the topic of Doleschal et al [1]. They familiarized the non-expert listeners to the sensations through an introduction phase where three sounds were presented to the listeners: an artificial prototypical sound that contained key features for the specific sensation, a recorded vehicle interior sound where the magnitude of the sensation was high and a third vehicle interior sound that did not elicit any of the three sensations.…”