Attention to Internet Explorer users: ROHM website does not recommend browsing in IE 11. Please use latest browser to ensure the best performance on ROHM website.
ROHM
Company Sustainability R&D Careers Contact Us
myROHM Login
  • Products
  • Technical Support
  • Applications
  • Sales
  • Buy or Sample
  • Products
  • Technical Support
  • Applications
  • Sales
  • Buy or Sample
myROHM Login
Company Sustainability R&D Careers Contact Us
  • Speech Synthesis LSI Selection Guide

  • Basic knowledge of audio data

  • Listening to compressed audio data

Speech Synthesis LSI Selection Guide (Voice Memory Size Calculator)

Calculate the required voice memory size for your system!

We calculate the voice memory size of your product and propose the best LAPIS Technology Speech Synthesis LSI.

1. Enter the basic settings of the Speech Synthesis LSI

Grade: :
CPU I/F :
Play time :

* The playback time is a guideline at a sampling frequency of 8.0kHz with 4bit ADPCM2.

Memory type :

2.  Input memory specifications and calculate memory size.

Synthesis
method
Number of
phrases
Average
length
of sound
Sampling
frequency
Approximate
memory
size

0
 Mbit

0
 Mbit

0
 Mbit

0
 Mbit

The total memory size for storing audio data is

0 Mbit

3. We propose the following LAPIS Technology Speech Synthesis LSI that is most suitable for your system.

Show/Hide
      Data
    sheets
    Supply
    Voltage
    (V)
    Frequency
    Band
    (MHz)
    Oscillator Operating
    Temperature
    (°C)
    ROM
    capacity
    (bit)
    Playback
    phrase
    count
    Maximum
    playback
    time(s)
    CPU
    I/F
    SP
    amplifier
    output
    (W)/class
    Mixing
    number
    (interna)
    (ch)
    Other PKG For
    automotive*1
    Sample
    and
    Buy
    • *1 :  is for automotive use.   can provide AEC-Q100 qualified products.

    Type of synthesis method

    Sampling frequency \ synthesis methodDescriptionSound qualityCompression ratioPlay time (sec)
    * When the audio data size is 1Mbit
    Bit
    rate
    MethodHuman voiceMusicsSound effectFs = 8kHzFs = 16kHzFs = 32kHz

    (Variable bit length)
    HQ-ADPCM *1

    LAPIS Technology's unique method.

    This method enables high compression while maintaining high sound quality by changing the bit rate to a variable bit length. This is the higher-order method of the following 4-bit ADPCM2.
    It is suitable for various sound qualities such as human voice, animal voice, nature sound, music and sound effects.
    We recommend this method for new development or when you want to change from another method to one with higher sound quality and higher compression.

    High-quality soundHigh-quality soundHigh-quality sound1/5402010

    4bit ADPCM2

    LAPIS Technology's unique method.

    The audio data is digitized at regular intervals, high compression is achieved by taking the difference from the previous data, and the sound quality is improved by improving the followability of the waveform.
    Suitable for expressing human voices, animal voices, and natural sounds.
    If you are currently using this method and want to change to a higher sound quality and higher compression method, we recommend the HQ-ADPCM method.

    High-quality soundLow sound qualityLow sound quality1/432168

    8bit non-linearPCM

    LAPIS Technology's unique method.

    By recording 10bits near the center of the waveform, high compression and high sound quality are realized.
    Suitable for expressing low volume sounds or human voice.
    If you are currently using this method and want to change to a higher sound quality, higher compression method, we recommend the HQ-ADPCM method.

    High-quality soundMedium sound qualityMedium sound quality1/21684

    8bit PCM

    This is a general method.

    It is suitable for expressions such as music and sound effects, and for sound effects and pulse-shaped waveforms with sharp changes in waveform.

    High-quality soundHigh-quality soundHigh-quality sound1/21684

    16bit PCM

    This is a general method.

    It is suitable for expressions such as music and sound effects, and for sound effects and pulse-shaped waveforms with sharp changes in waveform.

    High-quality soundHigh-quality soundHigh-quality sound1/1842
    • *1 : HQ-ADPCM is Ky's high-quality sound compression technology. Ky's is a registered trademark of Kyushu Institute of Technology.Ky's logo

    Phrase description

    phraseDescription

    Sampling Frequency (Fs)

    When converting an analog signal such as voice to a digital signal, this is a numerical value that indicates how many times (quantization) should be performed for 1 second of data.
    The unit is Hz. For example, sampling is performed 8,000 times per second at 8kHz, and 16,000 times per second at 16kHz.
    The higher the sampling frequency, the better the sound quality.
    (Sampling frequency of 44.1kHz for music CD and 48kHz for digital broadcasting.)

    Bit rate

    It is a numerical value when the amount of data uttered per second is expressed in bits.
    For data of the same format and sampling frequency, the higher the bit rate, the better the sound quality. However, the amount of data is large.

    Number of phrases

    The number of types of sound to play.
    For speech synthesis LSIs, this is the number of addresses that can be set.
    For example, when playing "This is LAPIS Technology", one phrase is used for "This is LAPIS Technology", and two phrases for "This is" and "LAPIS Technology".

    Sound effect

     
    Synthesis methodHQ-ADPCM4bit ADPCM28bit non-linear PCM8bit PCM16bit PCM

    32kHz

    PLAYPLAYPLAYPLAYPLAY

    16kHz

    PLAYPLAYPLAYPLAYPLAY

    8kHz

    PLAYPLAYPLAYPLAYPLAY

    Melody

    Synthesis methodHQ-ADPCM4bit ADPCM28bit non-linear PCM8bit PCM16bit PCM

    32kHz

    PLAYPLAYPLAYPLAYPLAY

    16kHz

    PLAYPLAYPLAYPLAYPLAY

    8kHz

    PLAYPLAYPLAYPLAYPLAY

    Guidance

    Synthesis methodHQ-ADPCM4bit ADPCM28bit non-linear PCM8bit PCM16bit PCM

    16kHz

    PLAYPLAYPLAYPLAYPLAY

    12kHz

    PLAYPLAYPLAYPLAYPLAY

    8kHz

    PLAYPLAYPLAYPLAYPLAY
    • * All copyrights of the sample audition sound source belong to our company and are protected by the Copyright Act. Unauthorized use of our sample listening sound source is prohibited by law.
    ROHMsemi    
    • Terms & Conditions for the usage of the website
    • Terms of Use of Social Networking Service
    • Privacy Policy
    • General Terms & Conditions of Contracts, Delivery & Services for Europe (English)
    • General Terms & Conditions of Contracts, Delivery & Services for Europe (German)
    • Impressum (Germany)
    • Standard Terms & Conditions for Sales
    • Sustainability
    • Research & Development
    • Patent Marking
    • Statement on UK Modern Slavery Act
    • ROHM UK Group Tax Strategy
    • Data Protection Information for Business Partners (Europe) [English]
    • Data Protection Information for Business Partners (Europe) [German]
    • Company
    • News
    • Investor Relations
    • Site Map
    • Contact Us
    • Lapis
    • Kionix
    • SiCrystal

    © 1997 - 2023 ROHM Co., Ltd. All rights reserved.

    Back to Top
    Please Wait...