ESP-SR Speech Recognition Framework

Espressif ESP-SR helps users build AI speech solutions based on ESP32 or ESP32-S3 chips.

Overview

ESP-SR framework includes the following modules:

• Audio Front-end AFE
• Wake Word Engine WakeNet
• Speech Command Word Recognition MultiNet
• Speech Synthesis

These algorithms are provided in the form of a component, so they can be integrated into your projects with minimum effort.

ESP32-S3 is recommended, which supports AI instructions and larger, high-speed octal SPI PSRAM. The new algorithms will no longer support ESP32 chips.

Wake Word Engine

Espressif wake word engine WakeNet is specially designed to provide a high performance and low memory footprint wake word detection algorithm for users, which enables devices always listen to wake words, such as “Alexa”, “Hi,lexin” and “Hi,ESP”.

Espressif has not only provided an official wake word "Hi,Lexin","Hi,ESP" to the public for free, but also allows customized wake words. For details on how to customize your own wake words, please see Espressif Speech Wake Words Customization Process or Training Wake Words by TTS sample.

The following wake words are supported in esp-sr:

wake words	ESP32	ESP32-S3
Hi,乐鑫	wn5_hilexin, wn5_hilexinX3	wn9_hilexin
你好小智	wn5_nihaoxiaozhi,wn5_nihaoxiaozhiX3	wn9_nihaoxiaozhi
小爱同学		wn9_xiaoaitongxue
Hi,ESP		wn9_hiesp
Hi,M Five		wn9_himfive
Alexa		wn9_alexa
Jarvis		wn9_jarvis_tts
Computer		wn9_computer_tts
Hey,Willow		wn9_heywillow_tts

NOTE: _tts suffix means this WakeNet model is trained by TTS samples.

Speech Command Recognition

Espressif's speech command recognition model MultiNet is specially designed to provide a flexible off-line speech command recognition model. With this model, you can easily add your own speech commands, eliminating the need to train model again.

Currently, Espressif MultiNet supports up to 300 Chinese or English speech commands, such as “打开空调” (Turn on the air conditioner) and “打开卧室灯” (Turn on the bedroom light).

The following MultiNet models are supported in esp-sr:

language	ESP32	ESP32-S3
Chinese	mn2_cn	mn5q8_cn, mn6_cn, mn7_cn
English		mn5q8_en, mn6_en, mn7_en

Audio Front End

Espressif Audio Front-End AFE integrates AEC (Acoustic Echo Cancellation), VAD (Voice Activity Detection), BSS (Blind Source Separation) and NS (Noise Suppression).

Our two-mic Audio Front-End (AFE) have been qualified as a “Software Audio Front-End Solution” for Amazon Alexa Built-in devices.

In order to achieve optimal performance:

• Please refer to software design esp-skainet.