Definitions of technical terms VR audio terms.
| Term | Definition |
|---|---|
| Anechoic | Producing no echoes; very low or no reverberation. |
| Attenuation | A loss of energy; in acoustics, typically a reduction in volume. |
| Direct Sound | Sound that has traveled directly to the listener without reflecting (versus reverberant sound). |
| Early Reflections | Reflected sounds that arrive relatively soon at a listener’s location (i.e., before Late Reflections). |
| Head-Related Impulse Response (HRIR) | A formal characterization of the effect of sound interacting with the geometry of a particular human body. Used to create head-related transfer functions. |
| Head-Related Transfer Function (HRTF) | A transformation of an acoustic signal using a head-related impulse response. Used to simulate the effects of interaction of a sound originating from a specific direction with the geometry of a particular human body. |
| Head Shadowing | The attenuation of sound caused by the head lying between an ear and the sound source. |
| Initial Time Delay | The interval between the arrival of a direct sound and its first reflection. |
| Interaural Level Difference (ILD) | The difference in a sound’s level or volume between the two ears. |
| Interaural Time Difference (ITD) | The length of the interval between when a sound arrives at the first ear and when it arrives as the second ear. |
| Late Reflections | Reflected sounds that arrive relatively late at a listener’s location (i.e., after early reflections). |
| Motion Parallax | When moving objects are father from a perceiver, their apparent speed of travel decreases; for example, a moving airplane on the horizon appears to be traveling more slowly than a nearby car. The apparent rate of travel of an object can therefore be used as a distance cue. |
| Pinnae | The visible portion of the ear that lies outside the head. |
| Reverberant Sound | Sound that has reflected or reverberated before arriving at a listener’s location (versus direct sound). |
| Reverberation | The reflection of sound off of a surface, or the temporary persistence of sound in a space caused by reverberation. |
| Sound Localization | 1. The process of determining the location of a sound’s origin; or 2. the suggestion of an object’s location based on the manipulation of auditory cues. |
| Sound Spatialization | The representation of a sound within three-dimensional space. |