The ConvolverNode performs real-time discrete convolution of an input audio stream with an Impulse Response (IR) audio buffer: y[n] = sum(x[k] * h[n-k]). An impulse response captures the acoustic signature of a physical space (such as a cathedral, concert hall, or metallic studio) by recording the sound of an ideal Dirac impulse as it bounces off walls and diffuses. The browser evaluates this using partitioned Fast Fourier Transforms (FFT) in frequency domain, applying complex multiplication to provide zero-latency convolution reverb with natural spectral coloration.

When PannerNode.panningModel is set to "HRTF", the Web Audio API simulates how human ears perceive three-dimensional sound directionality. The engine applies an empirical set of acoustic filters measured from human head mannequins (KEMAR). It calculates Interaural Time Difference (ITD - sound arriving at the near ear microseconds before the far ear), Interaural Level Difference (ILD - head acoustic shadow attenuating high frequencies in the far ear), and pinna reflections (folds of the outer ear that create frequency notches to disambiguate elevation and front-vs-back direction).

Yes. High-quality synthetic impulse responses can be programmatically generated directly into an AudioBuffer using mathematical exponential decay noise: IR(t) = n(t) * exp(-6.9078 * t / RT60), where n(t) is white or pink Gaussian noise and RT60 is the reverberation time (the time required for sound pressure level to drop by 60 dB). Adding discrete early reflection taps within the first 10-50 milliseconds and applying a 1-pole low-pass filter simulates high-frequency air and wall absorption.

Both ConvolverNode and HRTF PannerNode are computationally intensive. HRTF spatialization runs dual FIR/IIR filters per active sound source. ConvolverNode requires heavy FFT calculations that scale with impulse response length (e.g., a 4-second stereo IR at 48 kHz requires 384,000 samples). For optimal performance in games or interactive web experiences, developers should share a single master ConvolverNode via an auxiliary send bus (GainNode) rather than creating distinct convolvers per sound source, and reserve HRTF panning for primary gameplay emitters while using "equalpower" panning for background ambiance.