The Relationship Between Untrained Listener Perceptions and Disordered Voices

The ability of trained listeners to make judgments of voice quality has been well documented. This study is designed to investigate untrained listeners\u27 ability to make quality judgments of male and female produced normal, breathy, harsh, and hypernasal voice qualities. Research purposes are as follows: 1. To test if untrained listeners tend to reliably assign specific positive or negative descriptive adjectives according to vocal quality. 2. To determine if specific disordered vocal qualities carry more negative rating than others. A series of actors and actresses were trained to produce the disordered voice qualities of breathy, harsh, and hypernasal according to specific guidelines. Provisions were made to insure consistency in the recording and playback of the voice samples. Actors were used to produce the voice qualities to insure distinct differences. A total of 32 untrained listeners rated male- and female-produced normal, breathy, harsh, and hypernasal voice quality samples on a bipolar positive/negative rating scale. An analysis of variance indicated that untrained listeners rate normal and disordered voice qualities differently, but a similarity exists in the ratings of the three disordered voice qualities. Findings also show that male-produced voice qualities are rated in a different manner than female-produced voice qualities. Implications toward future research in related directions are presented. These include investigation of differences between ratings of male and female speakers and substantiation of the extent to which a disordered voice may inhibit interpersonal relations based on initial speaker/listener contact. Future related studies should improve validity by eliminating the extraneous variables identified by this study

The Relationship Between Untrained Listener Perceptions and Disordered Voices

The ability of trained listeners to make judgments of voice quality has been well documented. This study is designed to investigate untrained listeners\u27 ability to make quality judgments of male and female produced normal, breathy, harsh, and hypernasal voice qualities. Research purposes are as follows: 1. To test if untrained listeners tend to reliably assign specific positive or negative descriptive adjectives according to vocal quality. 2. To determine if specific disordered vocal qualities carry more negative rating than others. A series of actors and actresses were trained to produce the disordered voice qualities of breathy, harsh, and hypernasal according to specific guidelines. Provisions were made to insure consistency in the recording and playback of the voice samples. Actors were used to produce the voice qualities to insure distinct differences. A total of 32 untrained listeners rated male- and female-produced normal, breathy, harsh, and hypernasal voice quality samples on a bipolar positive/negative rating scale. An analysis of variance indicated that untrained listeners rate normal and disordered voice qualities differently, but a similarity exists in the ratings of the three disordered voice qualities. Findings also show that male-produced voice qualities are rated in a different manner than female-produced voice qualities. Implications toward future research in related directions are presented. These include investigation of differences between ratings of male and female speakers and substantiation of the extent to which a disordered voice may inhibit interpersonal relations based on initial speaker/listener contact. Future related studies should improve validity by eliminating the extraneous variables identified by this study

The reduction of gunshot noise and auditory risk through the use of firearm suppressors and low-velocity ammunition

<p><i>Objective:</i> This research assessed the reduction of peak levels, equivalent energy and sound power of firearm suppressors. <i>Design:</i> The first study evaluated the effect of three suppressors at four microphone positions around four firearms. The second study assessed the suppressor-related reduction of sound power with a 3 m hemispherical microphone array for two firearms. <i>Results:</i> The suppressors reduced exposures at the ear between 17 and 24 dB peak sound pressure level and reduced the 8 h equivalent A-weighted energy between 9 and 21 dB depending upon the firearm and ammunition. Noise reductions observed for the instructor’s position about a metre behind the shooter were between 20 and 28 dB peak sound pressure level and between 11 and 26 dB <i>L</i>_Aeq,8h. Firearm suppressors reduced the measured sound power levels between 2 and 23 dB. Sound power reductions were greater for the low-velocity ammunition than for the same firearms fired with high-velocity ammunition due to the effect of N-waves produced by a supersonic bullet. <i>Conclusions:</i> Firearm suppressors may reduce noise exposure, and the cumulative exposures of suppressed firearms can still present a significant hearing risk. Therefore, firearm users should always wear hearing protection whenever target shooting or hunting.</p