Our company specializes in developing musical greeting card sound module, traffic safety voice prompt module, elevator safety voice prompt module, safety prompt voice module… This product is a one-time recording voice IC (can provide 10 seconds, 20 seconds, 40 seconds and 80 seconds) module. The main features are fewer feet (8 feet), small size, and many forms of encapsulation (DIP SOP COB and bare die). Strong function (support for customer-defined sound source and function requirements, DAC and PWM drive, push motor and flash). There are a few peripherals. The operating voltage is 2V to 5V. Short delivery time, no order quantity limit.

The safe voice prompting device is widely applied. There are only a few typical application cases listed below.

1. High voltage area in the power system, security voice prompts in the military control area, the public security area.

2. Safety voice prompts in a production workshop and construction area.

3. Entering office building, business hall, waiting for plane (vehicle) building and guests welcoming prompts.

4. Plaza, supermarket, commercial outlets product advertising.

5. The Museum of science and technology, exhibition hall visit guidance or automatic explanation;

6. Bank, ATM teller machine fraud, theft prevention voice prompt;

7. Public places, hospitals, disabled persons to guide voice prompts;

8. Each industry security defense voice prompt.

Nine module electronic Electronics Co., Ltd. is a dedicated voice module developer. It specializes in voice module research and development and peripheral circuit development. The voice scheme has an MP3 video recording module/module scheme, repeatable erasable voice module/module scheme, OTP voice module scheme and so on, providing professional voice prompting scheme for customers. The nine-module electronic voice module is suitable for a variety of industries and has been involved in a variety of applications, allowing the product to enter a more intelligent and humanized level, so that the user’s experience is more comprehensive and convenient.

Speech compression can be divided into high bit rate (16~64KB/S), middle bit rate (4.8KB/S~16KB/S), low bit rate (2.4KB/S~4.8KB/S), and very low bit rate <2.4KB/S based on the code rate of the speech module. According to this classification method, the coding methods involved in speech module are divided into three categories: middle high rate coding, low rate, and very low rate coding.

In general, high rate coding is mainly based on speech waveform coding, which has strong adaptability, good quality of sound quality, relatively high single coding rate, large storage space and relatively wide bandwidth during transmission. The medium speed coding is based on the hybrid coding, based on the hypothesis of the speech generation model and the auditory model, and uses the analytical synthesis technology. At the same time, the naturalness of the reconstructed speech is enhanced by using the speech time waveform information. The low rate and extremely low rate coding are based on the parameter coding. By establishing the speech signal generation model, the representative speech signal features and parameters are extracted.

Medium and high-speed coding

Continuous variable slope delta modulation (CVSD) adjusts the increment of quantization step size for the amplitude variation rate of the input signal. If the amplitude change rate of the input signal increases, the increment is also adjusted accordingly. When the amplitude change rate of the input signal is reduced hourly and increasing green, the parameters are also reduced and adjusted accordingly. The prominent advantage of CVSD is that it has strong error resilience capability. The algorithm is simple and hard to implement, and there is no need to take synchronous measures when entering a single channel. Therefore, this code has been widely applied in satellite communications, mobile communications, and military communications.