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Sound chip

Integrated circuit designed to produce audio signals

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A sound chip is an integrated circuit (chip) designed to produce audio signals through digital, analog or mixed-mode electronics. Sound chips are typically fabricated on metal-oxide-semiconductor (MOS) mixed-signal chips that process audio signals. They normally contain audio components such as oscillators, envelope generators, samplers, filters, amplifiers.

01History

A number of sound synthesis methods for electronically producing sound were devised during the late 20th century. These include programmable sound generators (PSG), wavetable synthesis, and frequency modulation synthesis (FM synthesis). Such sound chips were widely used in arcade game system boards, video game consoles, home computers and digital synthesizers.

Since the late 1990s, pulse-code modulation (PCM) sampling has been the standard for many sound chips, as used in the Intel High Definition Audio (IHDA) standard of 2004. The PCM sampling method is used in many mobile phones and sound cards for personal computers. This widespread use is part of the digital sound revolution that started in the 1980s.

02Types

There are multiple types of sound chips, which are divided based on their use.

While traditional sound chips focus on general audio synthesis (e.g., in PCs or musical instruments), voice chips represent a specialized category optimized for voice-related applications. Based on market trends, they can be divided into five primary types, each with distinct technical characteristics and use cases.

Voice chips
TypeCore features
One-time programmable (OTP) voice chips
  • OTP, short playback duration, low audio quality, non-rewritable
  • Extremely low cost but high minimum order quantity
  • Example: Vehicle reversing alerts, simple toy prompts
Flash voice chips
  • Built-in or external flash storage, supports WAV encoding (e.g., WT588D, ISD series)
  • Require dedicated tools for voice burning, cumbersome operation
  • Moderate audio quality, no significant cost-performance advantage
MP3 voice chips
  • Dominant market solution with integrated MP3 decoding
  • Includes dedicated audio DSP, MCU, and external storage (e.g., TF cards)
  • Representative models: KT404A series, KT142C series
  • Advantages: USB voice updates, flexible volume control, combined playback (e.g., amounts/license plates/time)
  • Disadvantage: Higher power consumption (unsuitable for low-power toys)
Text-to-speech (TTS) voice chips
Voice dialog chips
  • Support local/cloud-based voice recognition
  • Local recognition: Low-end toys (e.g., voice-controlled dolls)
  • Cloud recognition: Requires Wi-Fi or mobile connectivity, higher latency
  • High-end solutions are costly

03Applications

Watch videos about Sound chipExplainers and documentaries on YouTube (opens in a new tab)

Sources and credits

This article is adapted from the Wikipedia article Sound chip, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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