Speech signal processing (II): phonation physiology, auditory physiology and auditory psychology

One 、 The source of voice

1、 vocal cords

The vocal cord of the throat is an organ that has a great influence on pronunciation .

The acoustic function of vocal cords is to provide the main excitation source for speech ;

Sound produced by the vibration of the vocal cords , It is the basic sound source of sound .

2、 fundamental frequency

The opening and closing of the vocal cords cause the air flow to form a series of pulses , The time of each opening and closing is the vibration period, which is called the pitch period , The reciprocal is called Pitch frequency .

3、 Characteristics of fundamental frequency

Depending on the size and characteristics of the vocal cords , It also depends on the tension it is under .

The fundamental frequency of vocal cord vibration determines the level of sound , A fast frequency makes a high tone , If the frequency is slow, the tone is low .

The pitch range is about 80-500HZ about , It depends on the gender of the speaker 、 Age depends on the circumstances , Older men are on the low side , Children and young women are on the high side .

4、 Three sound sources of speech

Speech is the sound made by human beings through their vocal organs by regulating the air flow generated by their respiratory organs . The air flow passes through different parts , In a different way , The sound is different . Whether the vocal cords vibrate or not is the key factor to determine the nature of the sound source .

The sound produced by the articulatory organ can be divided into three main sources .

4.1 Voiced sound source

When pronouncing , When air flows through the glottis , Vibrate the vocal cords , Produce periodic sound waves , It's voiced .

Dullness is the loudest , It is the most important sound source in speech . Sound samples ： Finals a

4.2 Turbulent sound source