School of English LOGO

The Phonetics Laboratory

School of English LOGO

Τμήμα Αγγλικής Γλώσσας και Φιλολογίας Α.Π.Θ.

Experimental Techniques

Experimental Techniques

In addition to the Kay CSL and the Electropalatograph, the following techniques are available in the lab:

Photo-electric Glottograph (Type LG 900)
This instrument gives information about the phonatory vibrations of the vocal cords. Cold light is led to the skin through an acryl rod and penetrates the tissue below the crico-thyroid cartilages. The light is picked up by a phototransducer inserted through the nostrils.

Electro-Glottograph (Type EG 830)
This instrument investigates different phonatory patterns of the vocal folds. It senses the electrical impedance of the human larynx by means of a pair of silver electrodes placed in contact with the skin on both sides of the larynx.

Electromyograph (Module EMG 2200)
This instrument records muscle activity through surface, needle or hooked-wire electrodes inserted in the muscles. The activity is given as a spike output in an oscilloscope or chart recorder. An Electrode Electrolyzer and EMG Tester (Type EMG 250) is used for cleansing the electrodes and for a general check of the EMG set-up before use.

Electro Aerometer (Type EA 510/4)
The Aerometer consists of a face mask with four airflow transducers, a microphone and an amplifier. The mask has separate mouth and nose sections consisting of inflated rubber rings which fit tightly around the mouth and nose. Through the airflow transducers the Electro Aerometer measures air flow during speech and registers all changes in the egressive and ingressive airstream from both nose and mouth.

Audio Frequency Filter (Type AFF 450)
This instrument is based on four active RC circuits: two low-pass and two high-pass filter circuits. Therefore it can be used as a filter for auditory tests, filtering of formants, extraction of fundamental frequency or as an accessory filter for use with the Intensity Meter.

Intensity Meter (Type IM 360)
This instrument registers the exact physical intensity of speech in absolute measures (watt/cm2 and dyn/cm2×sec) or in dB.

Fundamental Frequency Meter (Type FFM 650)
This meter extracts the fundamental frequency by means of band-pass filters which remove the harmonics in the speech spectrum. The Fundamental Frequency Meter in combination with the Intensity Meter permits examinations of acoustic relations between stress, intonation and duration.

Manophone (Type MF 710)
This instrument is intended for measurements of air pressure in the speech cavities. Measurements of oral and pharyngeal air pressures are carried out through plastic tubes inserted through the nose or between the lips. The subglottal air pressure can be measured by means of a cannula inserted into the trachea or an air-filled balloon in the esophagus inserted through the nose.

There is also a Mingocard 4 (Siemens - Elema), a Synchroscope (LBO 301), an Audio Generator (LAG-26), and an FJ Electronics’ Modular System.