async _call(audio) {
        validate_audio_inputs(audio, 'ASTFeatureExtractor');

        const features = await this._extract_fbank_features(audio, this.config.max_length);
        if (this.config.do_normalize) {
            // Normalize the input audio spectrogram to have mean=0, std=0.5
            const denom = this.std * 2;
            const features_data = features.data;
            for (let i = 0; i < features_data.length; ++i) {
                features_data[i] = (features_data[i] - this.mean) / denom;
            }
        }

        return {
            input_values: features.unsqueeze_(0)
        };
    }
Asynchronously extracts features from a given audio using the provided configuration.
@param {Float32Array|Float64Array} audio The audio data as a Float32Array/Float64Array.
@returns {Promise<{ input_values: Tensor }>} A Promise resolving to an object containing the extracted input features as a Tensor.