Nasal Flow of/a/,/i/,/?/and/n/,/?/Coarticulation for Male Adults / 听力学及言语疾病杂志

Objective To investigate acoustic characteristics of VC coarticulation for males in Mandarin . Methods This study compared nasal flow of 32 male adults'production which include /an/,/in/,/?n/,/a?/,/i?/,/??/,/a/,/i/,/?/.Results Whether /a /,/i/or /?/,the nasal flow of vowels before /n/was greater than the na-sal flow of vowels before /?/was greater than the nasal flow of vowels themselves .When produced solely ,the na-sal flow of /i/was greater than the nasal flow of /a/,/?/ .Before nasal consonants /n/,/?/ ,the nasal flow of /i/was greater than the nasal flow of /?/which was greater than the nasal flow of /a/.Conclusion Vowels before nasal consonants can be nasalized .The nasalization of /n/to vowel is greater than that of /?/to vowel .When nasals is produced around ,the nasalization of vowel depends on the height of the tongue .The nasal flow of vowels can be used as an effective measure and monitor the indicators before and after nasal coarticulatin .

Nasal spirometery.

Nasal obstruction is a common symptom which is difficult to quantify clinically. Rhinomanometry, Acoustic Rhinometry and Forced Oscillation methods are available for estimating nasal resistance but, these require sophisticated machines. Because of limited availability of these techniques, this potential physiological measure has not been tapped fully for research and clinical purposes. Here, we describe the use of pulmonary spirometer with little modification for quantification of nasal flow. Nasal inspiratory and expiratory flow rates along with oral inspiratory and expiratory flow rates are used to derive different nasal resistance indices. This way of reporting nasal resistance is not new but, the data for these variables is currently not available in published literature. The reproducibility of nasal flow rates were tested as variation after one day and the interclass coefficient for inspiratory and expiratory nasal flow rates were found to be with in acceptable limits. Thus, nasal spirometery is able to describe the nasal resistance in a reliable manner and may be used to quantify nasal obstruction in pathological condition and also to study the physiological phenomenon like nasal cycle.

Development of a Device Equipped with a Thermocouple for Measuring Nasal Airflow

BACKGROUND AND OBJECTIVES: To measure nasal cavity function as an airway, rhinomanometry and acoustic rhinometry are currently being used in clinical settings. However, these methods are not helpful for continuously measuring the aerodynamic status of both nasal cavities simultaneously. Therefore, a new instrument to evaluate the nasal flow is required. MATERIALS AND METHODS: To measure the airflow of bilateral nasal cavity simultaneously, two thermocouples are held in the headset, with the tips of thermocouples positioned below nostrils. The thermocouples are connected to the analog-digital converter and the digitized data is transferred to a notebook computer, in which a graphical programming language software is installed. Eighteen adults were recruited for this study who had no structural abnormality in their nasal cavities. For every subject, measurements from acoustic rhinometry, the thermocouple device, and rhinomanometry were taken in succession. The data from the thermocouple device was compared with those taken from the acoustic rhinometry and rhinomanometry. RESULTS: A negative correlation was noted between the minimum cross-sectional area by acoustic rhinometry and the inspiratory slope by thermocouple. No correlation was noted between the results for rhinomanometry and the thermocouple device. CONCLUSION: The thermocouple device has some advantages over other devices for its non-invasive, continuous, and real-time measurements and its ability to measure bilateral nasal cavity simultaneously.

The Shape of Expiratory Nasal Flow

The characteristics of the expiratory nasal flow consist of three parts - amount, content and shape. By far, most reports are confined only to the nasal resistance, nasal pressure, temperature, humidity and gas concentration of the expiratory nasal flow. There are few reports on the shape of the expiratory nasal flow. We aimed to visualize the expiratory nasal flow and to see whether there is any correlation between the shape of the expiratory nasal flow and the shape of the external nose. For each seven normal adult males and females, the shape of the expiratory flow was checked with infrared imaging thermometer placed on the frontal and sagittal planes. We also measured the external nasal indices and compared them with the shape of the nasal flow. We could see the shape of the expiratory nasal flow through the infrared imaging thermometer in real time. The mean of the angles formed by each side of the expiratory nasal flows on the frontal plane was 39 degrees, and the frontal angle showed good correlation with the shape of the external nose. The real-time visualization of the expiratory nasal flow, conducted with the infrared imaging thermometer, was an absolutely non-invasive technique and may be used to investigate nasal functions.