# KAD: No More FAD! An Effective and Efficient Evaluation Metric for Audio Generation

Source: [KAD: No More FAD! An Effective and Efficient Evaluation Metric for Audio Generation](<https://www.sota2.com/research/paper/68fa775e1e209131cea72c17>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-26T04:16:49.987Z

Authors: Yoonjin Chung, Pilsun Eu, Junwon Lee, Keunwoo Choi, Juhan Nam, Ben Sangbae Chon

Published: 2025-02-21T17:19:15.000Z

## Abstract

Although being widely adopted for evaluating generated audio signals, the Fr\\'echet Audio Distance (FAD) suffers from significant limitations, including reliance on Gaussian assumptions, sensitivity to sample size, and high computational complexity. As an alternative, we introduce the Kernel Audio Distance (KAD), a novel, distribution-free, unbiased, and computationally efficient metric based on Maximum Mean Discrepancy (MMD). Through analysis and empirical validation, we demonstrate KAD's advantages: (1) faster convergence with smaller sample sizes, enabling reliable evaluation with limited data; (2) lower computational cost, with scalable GPU acceleration; and (3) stronger alignment with human perceptual judgments. By leveraging advanced embeddings and characteristic kernels, KAD captures nuanced differences between real and generated audio. Open-sourced in the kadtk toolkit, KAD provides an efficient, reliable, and perceptually aligned benchmark for evaluating generative audio models.

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

- [Audio quality assessment on DCASE Task 7 System-level n=9 2023](<https://www.sota2.com/research/sota/audio-quality-assessment-on-dcase-task-7-system-level-n-9-2023.md>): Audio Quality Assessment; DCASE Task 7 System-level n=9 2023; FAD: not recorded.

- [Audio category-fit MOS correlation assessment on DCASE Task 7 2023 (test)](<https://www.sota2.com/research/sota/audio-category-fit-mos-correlation-assessment-on-dcase-task-7-2023-test.md>): Audio category-fit MOS correlation assessment; DCASE Task 7 2023 (test); FAD: not recorded.

- [Audio Quality Assessment on DCASE Task 7 Per-category n=63 2023](<https://www.sota2.com/research/sota/audio-quality-assessment-on-dcase-task-7-per-category-n-63-2023.md>): Audio Quality Assessment; DCASE Task 7 Per-category n=63 2023; FAD: not recorded.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/2502.15602>)

[PDF](<https://arxiv.org/pdf/2502.15602.pdf>)