X-ARES: eXtensive Audio Representation and Evaluation Suite

Introduction

X-ARES (pron /eks ˈeəz/) is an audio encoder benchmark that ​automatically trains task-specific output layers​ (including MLPs and k-NN) ​on user provided encoders. It is heavily inspired by the HEAR benchmark.

Users provide a single pretrained audioencoder, which outputs frame-level embeddings. Embeddings are evaluated using a fine-tuned MLP layer for clip- and frame-level tasks. Further a non-parameterized kNN algorithm is used to evaluate the quality of embeddings. For specialized tasks, pre-trained decoders are incorporated as task-specific components.

Supported tasks

Speech

• ASV2015
• CREMA-D
• Fluent Speech Commands
• LibriCount
• LibriSpeech-ASR
• LibriSpeech-Male-Female
• RAVDESS
• Speech Commands V2
• speechocean762
• VocalSound
• VoxCeleb1
• VoxLingua107

Environment

• Clotho
• DESED
• ESC-50
• FSD18-Kaggle
• FSD50k
• UrbanSound 8k
• Finger snap sound¹
• Inside/outside car¹
• Key scratching car¹
• LiveEnv sounds¹
• Subway broadcast¹

Music

• FMA
• GTZAN Genre
• MAESTRO
• NSynth

Installation

X-ARES is available on PyPI. You can install it via pip.

pip install xares

For development, you can clone the repository and install the package in editable mode.

git clone <this-repo>
cd xares
pip install -e .[examples]

Run with the baseline pretrained audio encoder (Dasheng)

You can run the benchmark with the baseline pretrained audio encoder (Dasheng) with 8 parallel jobs using the following command:

python -m xares.run --max-jobs 8 example/dasheng/dasheng_encoder.py src/tasks/*.py

It will download the datasets from Zenodo, and then evaluate the encoder on all the tasks. If the automatic download fails, you can also manually download the datasets using tools/download_manually.sh.

Alternatively, you can run tasks from within Python. Here is an example of running the ASVspoof2015 task in a single process:

>>> from example.dasheng.dasheng_encoder import DashengEncoder
>>> from tasks.asvspoof_task import asvspoof2015_config
>>> from xares.task import XaresTask

>>> task = XaresTask(config=asvspoof2015_config(encoder=DashengEncoder()))
>>> task.run()

Baseline Results

X-ARES provides two evaluation methods to assess the quality of audio representations: MLP (Linear Fine-Tuning) and kNN (Unparameterized Evaluation).

MLP: Linear Fine-Tuning on Task-Specific Data. A linear layer will be trained using the provided user embeddings, optimized with predefined hyperparameters for each task. This approach assesses how effectively the fixed representations can be adapted to specific tasks by training an additional linear layer, using predefined hyperparameters tailored for each task. This method evaluates the adaptability and effectiveness of the pre-trained models when applied to new, task-specific contexts without altering the original model parameters.

kNN: Unparameterized Evaluation. Pre-trained model embeddings will be used directly for K-nearest neighbor (KNN) classification without training. This method aims to evaluate the inherent quality of the audio representations without any fine-tuning. While this approach may not always yield the highest performance in real-world applications, it serves as a rigorous test of the fundamental representational power of the embeddings. By avoiding parameterized layers, this method provides a clear view of how well the model captures essential features of the audio data.

Here are the evaluation results for several baseline models using MLP and kNN methods. The weighted average is calculated using the test set size for each dataset.

MLP Result

Task	dasheng	wav2vec2	whisper	data2vec
ASV2015	0.964	0.924	0.966	0.937
Clotho	0.029	0.014	0.038	0.008
CREMA-D	0.767	0.541	0.572	0.523
DESED	0.537	0.313	0.127	0.136
ESC-50	0.857	0.510	0.528	0.229
Fluent Speech Commands	0.946	0.468	0.776	0.978
Free Music Archive Small	0.643	0.469	0.581	0.334
FSD50k	0.409	0.166	0.262	0.085
FSD18-Kaggle	0.534	0.241	0.241	0.153
GTZAN Genre	0.851	0.630	0.622	0.448
LibriCount	0.681	0.583	0.549	0.492
LibriSpeech-100h	0.608 (0.724 v0.1.3)	0.405 (0.545 v0.1.3)	0.721 (0.815 v0.1.3)	0.893 (0.866 v0.1.3)
LibriSpeech-MF	0.986	0.948	0.973	0.752
MAESTRO	0.524	0.180	0.011	0.116
NSynth-Instruments	0.688	0.443	0.532	0.336
RAVDESS	0.749	0.442	0.459	0.467
Speech Commands V1	0.969	0.714	0.933	0.927
UrbanSound 8k	0.833	0.659	0.687	0.426
Vocal Imitation	0.253	0.147	0.180	0.128
VocalSound	0.910	0.768	0.860	0.803
VoxCeleb1	0.780	0.340	0.388	0.105
VoxLingua33	0.814	0.553	0.873	0.620
Key scratching car1	0.999	0.983	0.985	0.909
Finger snap sound1	0.870	0.872	0.861	0.808
Inside/outside car1	0.972	0.928	0.866	0.869
Live Env 1	0.986	0.955	0.887	0.759
Subway broadcast1	0.972	0.930	0.942	0.869
Weighted Average (public tasks)	0.699	0.490	0.632	0.598
Weighted Average (all tasks)	0.801	0.664	0.740	0.694

kNN Result

Task	dasheng	wav2vec2	whisper	data2vec
ASV2015	0.869	0.858	0.843	0.942
CREMA-D	0.380	0.221	0.372	0.351
ESC-50	0.618	0.081	0.191	0.040
Fluent Speech Commands	0.260	0.017	0.032	0.630
Free Music Archive Small	0.592	0.251	0.406	0.106
GTZAN Genre	0.758	0.303	0.350	0.108
LibriCount	0.311	0.235	0.246	0.176
LibriSpeech-MF	0.791	0.606	0.617	0.724
NSynth-Instruments	0.499	0.251	0.205	0.179
RAVDESS	0.408	0.169	0.296	0.313
Speech Commands V1	0.903	0.208	0.096	0.852
UrbanSound 8k	0.662	0.339	0.215	0.156
Vocal Imitation	0.107	0.010	0.016	0.018
VocalSound	0.382	0.269	0.405	0.308
VoxCeleb1	0.262	0.003	0.010	0.033
VoxLingua33	0.376	0.034	0.360	0.058
Key scratching car1	0.955	0.923	0.691	0.550
Finger snap sound1	0.848	0.787	0.401	0.461
Inside/outside car1	0.798	0.575	0.730	0.588
Subway broadcast1	0.949	0.533	0.884	0.530
Weighted Average (public tasks)	0.504	0.262	0.299	0.388
Weighted Averag (all tasks)	0.683	0.469	0.475	0.455

Run with your own pretrained audio encoder

Examples of audio encoder wrapper could be found at examples, where the baseline encoders are implemented.

We provide a check function to verify if the encoder is correctly implemented:

>>> from xares.audio_encoder_checker import check_audio_encoder

>>> encoder = YourEncoder()
>>> check_audio_encoder(encoder)
True

And then you can run the benchmark with your own encoder:

python -m xares.run --max-jobs 8 your_encoder.py src/tasks/*.py

Notes on Encoder implementation

By sure that your encoder supports variable length inference up to 10 minutes of audio. We recommend to simply chunk the input audio in your encoder to mitigate any out-of-memory issues, like:

class MyCustomEncoder(torch.nn.Module):
    def __init__(self):
        super().__init__()
        self.sampling_rate = 16000
        self.output_dim = 512
        self.hop_size_in_ms = 10
        self.model = my_model_implementation()
        # This code is only for cases where the model itself does not implement chunking
        self.custom_max_audio_length = int(self.sampling_rate * 10)

    def forward(self, audio: torch.Tensor):
        if audio.ndim == 1:
            audio = audio.unsqueeze(0)

        self.model.eval()
        with torch.inference_mode():
            if audio.shape[-1] > self.custom_max_audio_length:
                embeds = []
                for chunk in audio.split(self.custom_max_audio_length, dim=-1):
                    if chunk.shape[-1] < self.sampling_rate:
                        chunk = torch.nn.functional.pad(
                            chunk, (0, self.sampling_rate - chunk.shape[-1]))

                    embed = self.model(chunk)
                    embeds.append(embed)
                encoded_audio = torch.cat(embeds, dim=1)
            else:
                encoded_audio = self.model(audio)

        return encoded_audio

Add new tasks

Adding a new task is easy. Refer to the existing task implementations for guidance. You need to create a TaskConfig tailored to your chosen dataset.

Citation

@inproceedings{zhang2025xares,
  title={X-ARES: A Comprehensive Framework for Assessing Audio Encoder Performance},
  author={Zhang, Junbo and Dinkel, Heinrich and Niu, Yadong and Liu, Chenyu and Cheng, Si and Zhao, Anbei and Luan, Jian},
  booktitle={Interspeech 2025},
  year={2025}
}

Footnotes

1. These tasks are private and use datasets that are not publicly available. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴