Voice command classification for mobile robotic control using mel frequency cepstral coefficients and support vector machines

Ratna Hartayu, Santoso Santoso, Ahmad Ridho’i, Ayusta Lukita Wardani, Yunus Awwalu Romadhon

Abstract

Voice command recognition plays a crucial role in enabling intuitive interaction in robotic and embedded control systems. This study proposes a voice command classification system based on Mel-frequency cepstral coefficients (MFCC) and support vector machine (SVM) using the Google speech commands dataset v2. Eight command classes (“down”, “go”, “left”, “no”, “right”, “stop”, “up”, and “yes”) were used. The dataset was divided into 80 % training and 20 % testing sets, with hyperparameter tuning performed using 5-fold cross-validation on the training data. MFCC feature extraction employed 13 static coefficients augmented with delta and delta-delta features, resulting in a 39-dimensional frame-level representation and a 78-dimensional utterance-level feature vector. Experimental results show that the SVM with radial basis function (RBF) kernel achieved optimal performance with parameters C = 100 and γ = 0.01, yielding 96.2 % accuracy, 96.5 % precision, 96.0 % recall, and 96.2 % F1 score. The inclusion of dynamic features improved accuracy by 4.7 % compared to static MFCCs. The system demonstrates a lightweight architecture suitable for low-resource environments; however, experiments were primarily conducted under clean conditions, and robustness evaluation was limited to a single noise level (20 dB SNR). Furthermore, real-time deployment on embedded hardware was not experimentally validated and remains part of future work.




Keywords


speech command recognition; MFCC; support vector machine; robot control; embedded systems

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R. Martinek, J. Vanus, J. Nedoma, M. Fridrich, J. Frnda, and A. Kawala-Sterniuk, “Voice communication in noisy environments in a smart house using hybrid LMS+ICA algorithm,” Sensors, vol. 20, no. 21, p. 6022, Jan. 2020.

F. Wang and X. Shen, “Research on speech emotion recognition based on teager energy operator coefficients and inverted mfcc feature fusion,” Electronics, vol. 12, no. 17, p. 3599, Jan. 2023.

M. Cenit and V. Gandhi, “Design and development of the sEMG-based exoskeleton strength enhancer for the legs,” J. Mechatron. Electr. Power Veh. Technol., vol. 11, no. 2, pp. 64–74, Dec. 2020.

J. Mishra, T. Malche, and A. Hirawat, “Embedded intelligence for smart home using tinyml approach to keyword spotting,” Eng. Proc., vol. 82, no. 1, p. 30, 2024.

E. Rijanto, E. Adiwiguna, A. P. Sadono, M. H. Nugraha, O. Mahendra, and R. D. Firmansyah, “A new design of embedded monitoring system for maintenance and performance monitoring of a cane harvester tractor,” J. Mechatron. Electr. Power Veh. Technol., vol. 11, no. 2, pp. 102–110, Dec. 2020.

L. Nwankwo and E. Rueckert, “The conversation is the command: interacting with real-world autonomous robot through natural language,” in Companion of the 2024 ACM/IEEE International Conference on Human Robot Interaction, Mar. 2024, pp. 808–812.

S. Tirronen, S. R. Kadiri, and P. Alku, “The effect of the MFCC frame length in automatic voice pathology detection,” J. Voice, vol. 38, no. 5, pp. 975–982, Sep. 2024.

B. Tracey et al., “Towards interpretable speech biomarkers: exploring MFCCs,” Sci. Rep., vol. 13, no. 1, p. 22787, Dec. 2023.

M. Maayah, A. Abunada, K. Al-Janahi, M. E. Ahmed, and J. Qadir, “Limit access: on-device tinyml based robust speech recognition and age classification,” Discov. Artif. Intell., vol. 3, no. 1, p. 8, Feb. 2023.

V. Verma et al., “A novel hybrid model integrating MFCC and acoustic parameters for voice disorder detection,” Sci. Rep., vol. 13, no. 1, p. 22719, Dec. 2023.

G. Cerutti, L. Cavigelli, R. Andri, M. Magno, E. Farella, and L. Benini, “Sub-mW keyword spotting on an mcu: analog binary feature extraction and binary neural networks,” IEEE Trans. Circuits Syst. Regul. Pap., vol. 69, no. 5, pp. 2002–2012, May 2022.

A. M. Rostami, A. Karimi, and M. A. Akhaee, “Keyword spotting in continuous speech using convolutional neural network,” Speech Commun., vol. 142, pp. 15–21, Jul. 2022.

Y. Cai, X. Li, and J. Li, “Emotion recognition using different sensors, emotion models, methods and datasets: a comprehensive review,” Sensors, vol. 23, no. 5, p. 2455, Jan. 2023.

A. M. Elshewey, M. Y. Shams, N. El-Rashidy, A. M. Elhady, S. M. Shohieb, and Z. Tarek, “Bayesian optimization with support vector machine model for parkinson disease classification,” Sensors, vol. 23, no. 4, p. 2085, Jan. 2023.

B. Kim and Y. Kwon, “Searching for effective preprocessing method and CNN based architecture with efficient

channel attention on speech emotion recognition,” Sci. Rep., vol. 15, no. 1, p. 32689, Sep. 2025.

J. Ancilin and A. Milton, “Improved speech emotion recognition with Mel frequency magnitude coefficient,” Appl. Acoust., vol. 179, p. 108046, Aug. 2021.

A. Hassan, T. Masood, H. A. Ahmed, H. M. Shahzad, and H. M. Tayyab Khushi, “Benchmarking pretrained models for speech emotion recognition: a focus on xception,” Computers, vol. 13, no. 12, p. 315, Dec. 2024.

A. Kuzdeuov, R. Gilmullin, B. Khakimov, and H. A. Varol, “An open-source tatar speech commands dataset for iot and robotics applications,” in IECON 2024 - 50th Annual Conference of the IEEE Industrial Electronics Society, Chicago, IL, USA: IEEE, Nov. 2024, pp. 1–5.

R. Sumikawa, A. Kosuge, Y.-C. Hsu, K. Shiba, M. Hamada, and T. Kuroda, “A183.4-nJ/inference 152.8- μ W 35-voice commands recognition wired-logic processor using algorithm-circuit co-optimization technique,” IEEE Solid-State Circuits Lett., vol. 7, pp. 2225, 2024.

Z. Kh. Abdul and A. K. Al-Talabani, “Mel frequency cepstral coefficient and its applications: A review,” IEEE Access, vol. 10, pp. 122136–122158, 2022.

Y.-L. Chen, N.-C. Wang, J.-F. Ciou, and R.-Q. Lin, “Combined bidirectional long short-term memory with mel-frequency cepstral coefficients using autoencoder for speaker recognition,” Appl. Sci., vol. 13, no. 12, p. 7008, Jan. 2023.

D. Cabrera, R. Medina, M. Cerrada, R.-V. Sánchez, E. Estupiñan, and C. Li, “Improved mel frequency cepstral coefficients for compressors and pumps fault diagnosis with deep learning models,” Appl. Sci., vol. 14, no. 5, p. 1710, Jan. 2024.

Santoso, T. A. Sardjono, and D. Purwanto, “Optimizing mel-frequency cepstral coefficients for improved robot speech command recognition accuracy,” in 2024 International Seminar on Application for Technology of Information and Communication (iSemantic), Semarang, Indonesia: IEEE, Sep. 2024, pp. 284–289.

J. Cervantes, F. Garcia-Lamont, L. Rodríguez-Mazahua, and A. Lopez, “A comprehensive survey on support vector machine classification: Applications, challenges and trends, ”Neurocomputing, vol. 408, pp. 189–215, Sep. 2020.

V. Blanco, A. Japón, and J. Puerto, “A mathematical programming approach to SVM-based classification with label noise,” Comput. Ind. Eng., vol. 172, p. 108611, Oct. 2022.

R. Guido, S. Ferrisi, D. Lofaro, and D. Conforti, “An overview on the advancements of support vector machine models in healthcare applications: A review,” Information, vol. 15, no. 4, p. 235, Apr. 2024.

K.-L. Du, B. Jiang, J. Lu, J. Hua, and M. N. S. Swamy, “Exploring kernel machines and support vector machines: principles, techniques, and future directions,” Mathematics, vol. 12, no. 24, p. 3935, Jan. 2024.

S. Shrivastava, S. Shukla, and N. Khare, “Support vector machine with eagle loss function,” Expert Syst. Appl., vol. 238, p. 122168, Mar. 2024.

O. Rainio, J. Teuho, and R. Klén, “Evaluation metrics and statistical tests for machine learning,” Sci. Rep., vol. 14, no. 1, p. 6086, Mar. 2024.

M. C. Hinojosa Lee, J. Braet, and J. Springael, “Performance metrics for multilabel emotion classification: Comparing micro, macro, and weighted f1-scores,” Appl. Sci., vol. 14, no. 21, p. 9863, Jan. 2024.

M. Conciatori, A. Valletta, and A. Segalini, “Improving the quality evaluation process of machine learning algorithms applied to landslide time series analysis,” Comput. Geosci., vol. 184, p. 105531, Feb. 2024.

S. Abdumalikov, J. Kim, and Y. Yoon, “Performance analysis and improvement of machine learning with various feature selection methods for eeg-based emotion classification,” Appl. Sci., vol. 14, no. 22, p. 10511, Jan. 2024.


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