Status of sound field audiometry among audiologists in the United States.

Abstract

Results of a national survey on sound field usage and sound field calibration are presented. The purposes of this study are: (1) to describe and analyze sound field stimuli, sound field test conditions, and sound field calibration procedures currently employed by audiologists nationwide, and (2) to investigate the extent of agreement between current practice and suggested practice from the current literature. Respondents to the survey were 418 ASHA certified audiologists, who answered questions on demographic variables, sound field testing conditions, and sound field calibration procedures. Eighty-one percent of the respondents use sound field audiometry as part of their audiological practice. Demographic characteristics of the respondents indicate that they were representative of the population of ASHA certified audiologists. Most respondents use two loudspeakers for sound field testing and use warbled pure tones for the stimuli. Forty-two different models of audiometers are in use, although three models account for over one-half of the responses. Electroacoustic calibration of the sound field stimuli is done most often by an equipment technician, and only a small percentage of the respondents knew how the calibration was done. No pattern of significant interactions was found among the calibration methods, sound field test conditions, and demographic variables of the subjects. Results show a lack of standardization among sound field test rooms, great diversity in the stimuli used for sound field testing, and inconsistent calibration methods. Results therefore indicate the need for national standards and improved pre-service and in-service training in sound field testing and sound field calibration techniques. Recommendations for clinical practice in sound field testing and sound field calibration are proposed.