Audio and Voice Software for NXP Microcontrollers



USB audio configuration

USB audio configuration

MCU Minutes | Alango Voice Enhancement Package Running on i.MX RT600 Crossover MCUs

MCU Minutes | Alango Voice Enhancement Package Running on i.MX RT600 Crossover MCUs thumbnail

Libraries and examples provided through MCUXpresso SDK

  • NXP has developed a range of audio libraries and collaborates with select partners to offer complementary specialized stacks. Each solution is fully integrated into the MCUXpresso SDK and comes with ready-to-use software examples to help you complete an in-depth evaluation and get started with your design


  • USB stack with device, host, and composite class support
  • USB Audio Class 2.0 (UAC2.0) examples
  • Source code provided
  • Complimentary for use on NXP devices
  • Bare metal or RTOS based
  • MCUXpresso Config Tool code generation for USB, with common USB presets

Essential Audio Processing

  • Bundle of audio processing blocks for enhancing the tonal perception of sound
  • Tuning tool for simulating EAP library processing behavior
  • Complimentary pre-compiled library for use on NXP devices

Partner Audio and Voice Solutions

  • Advanced audio/voice system design tools
  • High-performance, preprocessing for voice recognition
  • Solutions for human-to-human communications


The NXP USB Stack is an Enabling Software Technology provided within the MCUXpresso SDK. The stack is architected into several layers to help application developers concentrate on developing the application instead of being concerned with communications related to low-level USB controller as well as the common framework defined in the USB 2.0 Specification for Host and Device Classes (including USB Audio).

The USB interface is well-suited for transport of audio ranging from low-fidelity voice connections to high-quality, multichannel audio streams. Many applications, from communications to entertainment to music recording and playback, can take advantage of the USB audio features.

MCUXpresso SDK examples support USB Audio Class 1.0 and 2.0. Starting with SDK v2.8.0, UAC2.0 is configured as the default implementation. For previous SDK v2.x releases, refer to select the USB device config header for USB audio class defines. Specific USB Audio examples can be found on some NXP development boards, depending on their capabilities.

  • USB Audio Class 2.0 device examples
    • 2-Channel audio input (microphone / line-In)
    • 2-Channel audio output (speaker / line-Out)
    • Composite HID (keyboard) + 2-channel audio input (microphone / line-in)
    • Composite HID (keyboard) + 2-channel audio input / output
    • Composite CDC (serial COM) + 2-channel audio input / output
    • ROM based USB device for 2-channel audio input (microphone / line-in)
    • ROM based USB device for 2-channel audio input / output
  • USB audio host examples
    • 2-Channel audio speaker (supporting an externally connected USB speaker)

USB Audio Device Support

Device Family* Arm® Cortex® Core HOST DEVICE ROM
K2x Cortex-M4
K6x Cortex-M4
K8x Cortex-M4
K32 L2x Cortex-M0+
K32 L3x Cortex-M4
LPC51U68 Cortex-M0+
LPC5411x Cortex-M4 + Cortex-M0+
LPC54S/540xx Cortex-M4
LPC54S018JxM Cortex-M4
LPC546xx Cortex-M4
LPC551x/S1x Cortex-M33
LPC552x/S2x Cortex-M33
LPC55S6x Dual Cortex-M33
i.MX RT6xx Cortex-M33 + Cadence® Tensilicia® HiFi 4
i.MX RT101x Cortex-M7
i.MX RT102x Cortex-M7
i.MX RT105x Cortex-M7
i.MX RT106x Cortex-M7
i.MX RT1170 Cortex-M7 + Cortex-M4

*Functionality may not be available on all parts within families listed above.

Essential Audio Processing

Essential Audio Processing (EAP) is a bundle of audio processing blocks from NXP available in the MCUXpresso SDK for supported devices in the form of a pre-compiled library. The features included in EAP help enhance the tonal and spatial perception of the audio, resulting in an improved listening experience. Currently, EAP supports the following list of sound processing algorithms:

  • 3D virtualization: concert sound or cinema sound
  • Speaker equalizer
  • User equalizer
  • Bass enhancement (pure bass or digital bass enhancement)
  • Volume control
  • Treble enhancement
  • Loudness maximiser
  • Auto volume leveler
  • Tone generator
  • Parametric spectrum analyzer

The EAP libraries are accompanied by a Tuning Tool, which allows you to simulate the behavior of the EAP library, listen to and compare the audio effects, and export your parameters to a compliant C header file.

Device Family Core Co-Proccessor EAP Recommended Evaluation Board(s)
i.MX RT600 Cortex-M33 Cadence® Tensilica® HiFi 4 audio DSP MIMXRT685-EVK

Partner Audio and Voice Solutions

NXP has partnered with leaders in the area of audio and voice technology to enable a range of specialized, high-performance solutions on a range of NXP MCUs based on Arm® Cortex®-M cores.


Alango’s DSP/MCU sound processing software technologies improve the quality of voice communication and enhance the audio experience in automotive hands-free systems, Bluetooth-enabled headsets, smart speakers, mobile and cordless phones, high-end audio/video conferencing systems, intercom systems, laptops, office speakerphones, tablets, assistive listening and hearing enhancement devices.

Products available from Alango for NXP MCUs based on Cortex-M technology are shown below. Alango products also support several of NXP’s i.MX applications processors.

Alango Product Overview i.MX RT600
Cortex-M33-based MCU + Cadence Tensilica HiFi 4 DSP
i.MX RT10xx
Cortex-M7-based MCUs
Audio Enhancement Technologies

Alango's suite of DP post processing technologies.

ListenThrough ambient awareness intelligently passes through only important sounds.

Automatic Volume and Equalization (AVQ) adjusts audio volume and spectrum in proportion to ambient noise spectrum.

PersonaSound automatically personalizes all sound output (e.g. music, radio, phone calls, navigation prompts) to match a person’s unique hearing preferences.

MuRefiner optimizes stereo, enhances spectral components, and adjusts bass.

OnlyVoice OnlyVoice is Alango’s advanced voice acquisition technology for true wireless (TWS) earphones, Bluetooth-enabled headphones and earbuds, and high-performance headsets.
Voice Activity Detection (VAD) Alango’s Voice Activity Detection (VAD) technology reliably detects human speech in an acoustic signal. The technology is based on a proprietary, high-resolution spectral noise estimation algorithm operating in real time.
Voice Communication Package (VCP) Voice Communication Package (VCP) is a universal software package of digital signal processing technologies for voice applications enabling high quality, full duplex, and noise-free communication from various environments.
Voice Enhancement Package (VEP) Voice Enhancement Package (VEP) is a suite of real-time software DSP technologies designed for improving speech recognition performance in voice-controlled multimedia devices.

DSP Concepts

Create, tune, and productize audio features with Audio Weaver Designer, a low code, drag and drop real-time interface with live module inspectors and over 400 different audio building blocks. Deploy highly optimized audio with AWE Core for NXP's MCUs that are best suited for audio processing. Customize your own playback sound and combine it with TalkTo, an audio front end, to implement a high performance voice control system. TalkTo detects and extracts faint voice commands in extremely noisy environments.

Products available from DSP Concepts for NXP Arm® Cortex®-M-based microcontrollers are shown below. DSP Concepts products also support several of NXP’s i.MX applications processors.

DSP Concepts Product Overview i.MX RT600
Arm® Cortex® M33 plus Cadence Xtensa HiFi4 DSP
i.MX RT10xx
Cortex-M7-based MCUs
Audio Weaver Designer A low code, drag and drop real-time interface with live module inspectors and over 400 different audio building blocks to integrate or create advanced audio features quickly.
AWE Core A cross-platform audio-processing engine that’s hand-optimized for NXP's microcontrollers that are best suited for audio processing. It features a library of over 400 audio building-blocks that are used to rapidly build and deliver cutting-edge audio features.
Asynchronous Sample Rate Converter A software-based solution for embedded products with multiple audio I/O streams, such as local microphones and speakers, Bluetooth, USB, and WiFi.
TalkTo TalkTo, an audio front end, is a high performance the voice control system. TalkTo detects and extracts faint voice commands in extremely noisy environments.