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Speech Synthesis LSI

Test Play of Speech Samples , Basic Knowledge of Speech Data , Sound Data Creation Support Flow

Test Play of Speech Samples , Basic Knowledge of Speech Data , Sound Data Creation Support Flow

Sound effects test play of various sampling frequencies and synthesis methods


  • English
  • Chinese
  • Effects
  • Music

The sample file is played by clicking the each speaker icon.

Synthesis Methods/Sampling Frequency ADPCM2 PCM Non-linear PCM
4bit 16bit 8bit 8bit
44.1kHz
42.7kHz
32kHz
25.6kHz
21.3kHz
16kHz
12.8kHz
10.6kHz
8kHz
6.4kHz
5.3kHz
4kHz
  • The actual sound quality depends on PC sound card and speaker.
  • Please check the actual sound quality of LSI via the evaluation board.

The sample file is played by clicking the each speaker icon.

Synthesis Methods/Sampling Frequency ADPCM2 PCM Non-linear PCM
4bit 16bit 8bit 8bit
44.1kHz
42.7kHz
32kHz
25.6kHz
21.3kHz
16kHz
12.8kHz
10.6kHz
8kHz
6.4kHz
5.3kHz
4kHz
  • The actual sound quality depends on PC sound card and speaker.
  • Please check the actual sound quality of LSI via the evaluation board.

The sample file is played by clicking the each speaker icon.

Synthesis Methods/Sampling Frequency ADPCM2 PCM Non-linear PCM
4bit 16bit 8bit 8bit
44.1kHz
42.7kHz
32kHz
25.6kHz
21.3kHz
16kHz
12.8kHz
10.6kHz
8kHz
6.4kHz
5.3kHz
4kHz
  • The actual sound quality depends on PC sound card and speaker.
  • Please check the actual sound quality of LSI via the evaluation board.

The sample file is played by clicking the each speaker icon.

Synthesis Methods/Sampling Frequency ADPCM2 PCM Non-linear PCM
4bit 16bit 8bit 8bit
44.1kHz
42.7kHz
32kHz
25.6kHz
21.3kHz
16kHz
12.8kHz
10.6kHz
8kHz
6.4kHz
5.3kHz
4kHz
  • The actual sound quality depends on PC sound card and speaker.
  • Please check the actual sound quality of LSI via the evaluation board.

Relationship between Sampling Frequency and Bit Rate


Sampling Frequency

Denotes the number of times per second an analog signal is converted (quantized) into digital. Generally, CDs are sampled at a rate of 44.1kHz. The higher the sampling rate the better the quality.

Ex)
8kHz is sampled in 8,000times/sec.
16kHz is sample in 16,000times/sec.

Bit Rate

Indicates the number of bits transferred per second.
The higher the bit rate the better the quality (at a given sampling rate). However, the file size increases as well.

Ex)
The number of bits of 4bit ADPCM2 is 4bit.
The number of bits of 8bit PCM is 8bit.

As shown in the formula below, the playback time can be calculated by dividing the memory capacity by the bitrate.

〈Memory Capacity〉
This refers to the memory capacity of the speech synthesis LSI. The larger the memory capacity the longer the playback time. The capacity is calculated in bits.

1Mbit=1,024Kbit , 1Kbit=1,024bit

Ex)
4Mbits=4×1024×1024=4194304bits


Features of Synthesis Methods



Synthesis
Methods
Features Applications
ADPCM2 LAPIS Semiconductor's unique compression method.
It expresses the sound data in numbers with constant intervals.
The data quantity is reduced by the difference from previous data.
The compression rate of this method is the highest.
Ideal for expressing human voice, animal voice, and nature sound.
PCM The highest sound quality but lowest compression rate among 4 methods. Ideal for expressing music and sound effects.
Non-linear
8bitPCM
LAPIS Semiconductor's unique method.
Records in 10bit near the center of waveform.
Ideal for expressing low human voice.