When it comes to speech, what will be the first thing popping up in your mind?
Effortless. I believe this is the first instinct for most of us when it comes to speech. Most people take "speaking" for granted. Production of speech sounds is almost par for the course. However, we never notice how much effort and planning we should do to produce a mere sound, not to mention a word or even a phrase. When we are to produce a sound, we will come up with an intention to form a speech component; then, this intention will direct the muscles of your oral organs, i.e. articulators, to move in a proper manner to reach the targeted sound. For example, if you are to produce the "p" sound for "pat," your intention will make you first move both of your upper and lower lips together to form a tight constriction without creating any vocal fold vibration to maintian the voiceless quality of "p." A release of the tight closure with a strong burst of breath will be followed to complete the production of "p." It is hard to imagine how delicate the whole process is if we take speech production for granted. PhonPage aims to tell you the truth that speech prodcution is in fact a gift from nature, and to reveal the underlying mechanism for human speech organization.
Articulatory phonetics (AP) is the subject that studies how speech sounds are produced, with a focus on the detailed articulatory movement and mechanism of speech sounds. It is a sub-field of phonetics, a branch of linguistics, which investigates how speech sounds are produced and perceived. Before we dive into the sea of AP, it is of importance to have some basic ideas about the fundamental tools that we use to produce various kinds of sounds; that is, our oral organs!
What are articulators? Time to open your mouth!
The above figure shows the oral organs we use while speaking. The articulatoy organs are generally divided into two parts: passive articulators and active articulators. The sound is generated by vocal fold vibration, and further modified by the oral cavity (and nasal cavity). When active articulators move to approach different passive articulators, the resonance cavity will be molded into different shapes, filtering the source sounds to create various speech sounds. Now, let's take a look at the articulators in the oral cavity.
Active Articulators
The active articulators refer to the flexible oral organs in the oral cavity. In other words, those articulators can move freely and proactively touch or approach passive articulators. Active articulators include the tongue and the lower lip (jaw). Our tongue is a large piece of flesh formed by various kinds of muscles. Therefore, it can move forward and backward to form constrictions or narrowings in the oral cavity. Tongue can be further divided into three parts as a fucntion of where the portion locates: tongue tip (apex), tongue blade (body) and tonge root (back), from anterior to the posterior of the tongue.
The other active articualtor is our lower lip. Some researchers regard both of upper and lower lips as active articulators. However, since the mobility of the upper lip is much restricted than the lower lip, the latter one is taken as the primary active labial articualtor here. But by definition, both lips could be counted as active articualtors for they do move upwards and dowwards.
Passive Articulators
The passive articulators refer to the fixed oral organs in the oral cavity. In other words, those articulators cannot be moved and can only be passively approached. Passive articulators generally consist of six portions: an upper lip, teeth, an alveolar ridge, a hard palate, a soft palate (velum) and a uvula, from the anterior to the posterior part of the upper gingiva. Our alvoelar ridge is located at the blue area right behind the upper front teeth, as shown in the figure. Extended from the alveolar ridge, the area in light green lies the hard palate. Hard palate is thin horizontal plate on the roof of the oral cavity. In the posterior part of the roof, a soft tissue called velum is located in the dark green area in the figure. The velum has a dangling portion hanging down the pharyngeal port, i.e. the uvula.
When we are speaking, the active articualtors (primarily the tongue) move close to or away from the passive articulators and it results in diverse oral cavity shapes. The cooperation between active and passive articulators help us to produce rich variety of speech sounds!