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Oído is an open-source speech-to-text engine designed to transcribe sentences offline on an ESP32-S3, rather than recognize only a fixed list of commands. Its documented target is a specific ESP32-S3 board configuration with 16 MB flash and 8 MB octal PSRAM; published accuracy figures are project-reported, and the latest status reviewed says physical-board speed measurements were still pending.
What Oído does—and what “without a command list” means
Oído is Lokutor’s speech-to-text engine for the ESP32-S3. Its intended use is open-vocabulary transcription: the system produces text from spoken sentences instead of matching speech against a finite set of commands configured in advance. Lokutor describes it as running entirely on-device, without cloud inference or a neural accelerator. The repository lists English and Spanish models. Oído repository
This differs from Espressif’s MultiNet, which Espressif describes as offline speech command recognition supporting up to 300 Chinese or English commands. Command recognition and sentence transcription are different tasks, so their reported benchmark figures are not a like-for-like contest. Espressif ESP-SR repository
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →The project name refers to “¡Oído!”, a Spanish kitchen expression used to confirm that an order was heard. Lokutor’s October 1, 2026 launch announcement
#1 Best Overall
- 🔥【Dual Mode & High Performance】 The ESP32-S3 development board features integrated dual-core xtensa 32-bit LX7 microprocessor, clock speed up to 240 MHz, with 16MB Flash and 8 MB PSRAM. Perfect for Arduino IoT projects requiring stable wireless communication with ultra-low power consumption.
- 🔧【Easy Programming & Debugging】 Equipped with dual USB Type-C ports, this ESP32-S3 board supports both USB and UART modes for effortless programming, firmware flashing, and debugging.
- 🌐【Versatile Wireless Connectivity】 Built-in Wi-Fi (2.4GHz) and Bluetooth 5.0 (LE) dual-mode ensure seamless connectivity with a wide range of smart devices, making it ideal for IoT, smart homes projects.
- 🚀【Flexible Download Options】 Supports dual download methods — USB direct download or USB-to-serial download — offering flexibility and convenience for different development needs.Ideal for beginners and developers working with ESP32-S3.
- 🔋【Advanced Power-Saving Modes】 Designed for energy-efficient applications, with 3.3V SPI voltage, the ESP32-S3 board supports multiple low-power modes, allowing you to extend battery life based on different usage scenarios.
What hardware the documented setup requires
The README specifies an ESP32-S3 N16R8 configuration: 16 MB of flash and 8 MB of octal PSRAM. It names an ESP32-S3-DevKitC-1 N16R8 and an INMP441 I2S microphone. An optional 0.96-inch SSD1306 OLED can display the live transcript; it is not a prerequisite. Oído repository
Check the exact memory configuration before choosing a board. A listing that says only “ESP32-S3” does not establish that it has the flash and PSRAM required by the documented setup.
Rank #2
- ESP32-S3-DevKitC-1-N16R8 SPI voltage: 3.3v, ESP32-S3-DevKitC-1 is an entry-level development board equipped with Wi-Fi + Bluetooth module ESP32-S3
- Most of the I/O pins on the module are broken out to the pin headers on both sides of this board for easy interfacing. Developers can either connect peripherals with jumper wires or mount ESP32-S3-DevKitC on a breadboard.
- The ESP32-S3-DevKitC development board equipped with ESP32-S3-DevKitC-1-N16R8, a general-purpose Wi-Fi + Bluetooth LE MCU module that integrates complete Wi-Fi and Bluetooth LE functions.
- ESP32-S3-N16R8 cable can be used: USB Type A to Type-C cable or CC cable Note the distinction between the commonly used USB A port to Type-C cable that can only be charged, which cannot be used for communication between YD-ESP32-S3 and the host.
- USB-to-UART Port and ESP32-S3 USB Port (either one or both), default power supply (recommended)
Microphone and optional display wiring
| Component | Connection |
|---|---|
| INMP441 microphone | SCK to GPIO4; WS to GPIO5; SD to GPIO6; L/R to ground |
| Optional SSD1306 OLED | SDA to GPIO8; SCL to GPIO9 |
The repository also describes a host CLI and live microphone demo, so you can try the host build without an ESP32-S3 board. The launch announcement lists Python dependencies including NumPy, soundfile, SentencePiece, and sounddevice, alongside build and run commands. Oído repository · Lokutor launch announcement
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Which model profile fits your priorities?
Oído’s English profiles trade flash use, transcription accuracy, and when text appears. Word error rate (WER) counts transcription errors relative to reference words; lower is better. The following figures are from Lokutor’s repository status dated October 2, 2026, and are project-reported LibriSpeech results—not independent reproductions. Oído repository
Rank #3
- 【Low-power performance】: The AYWHP ESP32-S3 Core development board integrates a 2.4 GHz Wi-Fi and Bluetooth 5 (LE) dual-mode communication module, perfect for Arduino Internet of Things (IoT) projects.
- 【Simple programming and debugging】: The ESP32-S3 module makes it easy to program and burn in your ESP32-S3 board via dual USB Type-C ports, with a choice of USB or UART modes.
- 【Multiple Power Saving Modes】: The ESP S3 development board supports multiple low-power modes, which can be configured according to different application scenarios to provide longer battery life.
- 【Dual download modes】: The ESP S3-1 module supports both USB direct connection download and USB to serial port download, providing more flexibility and convenience.
- 【Diverse connectivity options】: The ESP32-S3-1 supports dual-mode Wi-Fi and Bluetooth 5.0 (LE) connectivity for a wide range of smart devices, making it ideal for Internet of Things (IoT) applications.
| English profile | LibriSpeech test-clean WER | LibriSpeech test-other WER | Model size / behavior |
|---|---|---|---|
| int8, greedy decoding | 3.7% | 8.2% | 14.0 MB model |
| int8, language model and beam search | 3.3% | 7.2% | 14.0 MB int8 model plus 1.3 MB language model |
| int4, greedy decoding | 4.6% | 10.0% | 8.3 MB model |
| int4 with language model | 3.8% | 8.4% | 8.3 MB int4 model plus 1.3 MB language model |
| Streaming English with language model | 4.9% | 11.0% | Provides partial text while speaking; the repository does not state a model-size figure for this row |
The int4 variant is the smaller listed model, while the optional language model improves the reported WER in the listed int8 and int4 comparisons. Streaming is for cases where partial text and lower latency matter more than the best listed accuracy; it has higher WER than the corresponding utterance-style results shown above. The repository does not give a latency measurement in this table. Oído repository
Spanish results
The repository reports Spanish WER with the language model on four datasets: 13.3% on Common Voice, 10.6% on Multilingual LibriSpeech, 15.5% on VoxPopuli, and 11.3% on FLEURS. These are project-reported figures, and they should not be compared directly with the English LibriSpeech results because the datasets differ. The repository lists separate English and Spanish model files and says there is no bilingual model. Oído repository
Rank #4
- 【ESP32-S3 PERFORMANCE】Dual-core 240MHz processor with 16MB Flash and 8MB PSRAM for IoT, AI, and machine learning projects.
- 【WIRELESS CONNECTIVITY】Onboard antenna for 2.4GHz WiFi and Bluetooth 5.0 LE — for smart home devices, no external antenna needed.
- 【LEAD-FREE GOLD EDITION DESIGN】Immersion gold (ENIG) plating for durability and conductivity. Lead-free, RoHS-compliant — for long-term prototyping.
- 【PRE-SOLDERED, PLUG-IN DESIGN】ESP32-S3 boards come with pre-soldered headers and plug directly into the included expansion and terminal boards — no soldering required.
- 【MULTI-PLATFORM COMPATIBILITY】Works with C++, MicroPython, ESP-IDF, Raspberry Pi, and STM32 — with online tutorials for quick start. Power via USB-C (5V) or VIN pin (5–12V); do not exceed 5V on the USB-C ports.
Why MultiNet numbers need context
Lokutor’s comparison table reproduces Espressif MultiNet7 figures of 8.5% test-clean and 21.3% test-other. Those values are for a command-recognition system, not open-vocabulary sentence transcription, so they do not establish a direct performance advantage for one system on the same task. Oído repository · Espressif ESP-SR repository
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Repair Windows errors before they cause bigger problems3Fix the driver behind crashes, sound loss and screen glitchesHow much of the performance is confirmed on a physical board?
The accuracy figures above come from Oído’s host build, which the repository says compiles the same C code as the firmware. Lokutor says firmware transcripts in Espressif’s QEMU emulator matched the host on most utterances, though numerical rounding differences can affect some difficult or noisy clips. The project estimates real-time speed from emulator instruction counts; its October 2, 2026 status note says physical-board measurements were still pending. Oído repository
Best Value
- 【GOLD EDITION — IMMERSION GOLD PCB】The Lonely Binary Gold Edition features a black PCB with lead-free immersion gold (ENIG) plating and clear silkscreen — the signature finish of the Lonely Binary Gold Edition line. RoHS-compliant.
- 【16MB FLASH + 8MB PSRAM】Large memory capacity for OTA updates, large programs, and AI/ML tasks — more headroom than 4MB boards for data-intensive IoT and automation projects.
- 【EXTERNAL IPEX ANTENNA】External IPEX antenna can be positioned for extended WiFi and Bluetooth signal coverage — for remote applications like weather stations, robots, or enclosed builds.
- 【DUAL USB TYPE-C PORTS】Separate power and data ports for macOS, Windows, and Linux. Power via USB-C (5V) or VIN pin (5–12V); do not exceed 5V on the USB-C ports.
- 【FLEXIBLE PROTOTYPING PINS】2x40-pin GPIO headers compatible with breadboards and sensors. Supports external ToF sensors via I2C for distance sensing.
The October 1, 2026 launch post likewise says demo transcripts are sped up and that physical-board footage was forthcoming. Treat the published results as project-reported accuracy and emulator/host validation—not proof of a measured real-time transcription rate on an actual board. Lokutor launch announcement
Practical limits to consider
- Language coverage: The repository lists English and Spanish models, with separate files rather than a bilingual model. Oído repository
- Timing: Utterance mode produces text after speech ends; streaming can show partial text but reports lower accuracy. Oído repository
- Acoustic conditions: The project says very noisy crowds and reverberant rooms remain difficult. Oído repository
- Memory: The documented board target requires the N16R8 memory configuration; an ESP32-S3 with unspecified memory is not enough to confirm suitability. Oído repository
Licenses and commercial products
The repository identifies the code as GNU GPLv3, but model files have their own licenses. It lists nemo8.tnm under CC-BY-4.0; nemo4.tnm and the English streaming model under CC-BY-SA-4.0; the optional language model under CC-BY-4.0; and the Spanish model and Spanish language model under CC-BY-4.0. Review the license applying to every code and model file you use. Oído repository
Lokutor says it offers commercial licenses and support for products that cannot meet GPLv3 terms, including consumer devices that do not let users install modified firmware. The announcement and repository do not state commercial-license pricing or eligibility details. Oído repository · Lokutor launch announcement
Quick Recap
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