Ambient noise impact on accuracy of automated hearing assessment.

OBJECTIVE: The aim of this study was to determine the effect of ambient noise on the accuracy of thresholds obtained using the KUDUwave portable clinical audiometer as compared to those obtained using a GSI-61 clinical audiometer in a sound booth. DESIGN: Pure-tone air conduction thresholds were obtained in three conditions: (1) with a clinical audiometer in a quiet sound booth, (2) with the KUDUwave in a quiet sound booth, and (3) with the KUDUwave with 40 dBA of background noise. STUDY SAMPLE: A total of 31 individuals ranging in age from 15 to 80 years participated in the study, 21 with normal hearing and ten with hearing loss. RESULTS: Eighty-nine percent of thresholds obtained with the KUDUwave in quiet, and 92% of thresholds obtained with the KUDUwave in background noise were within 5 dB of those obtained with the clinical audiometer. Accuracy was poorer at 250 Hz and 8000 Hz. CONCLUSION: Ambient noise typical of that found in a non-sound-treated room, did not affect the accuracy of air conduction hearing thresholds obtained with the KUDUwave. The KUDUwave may be a viable method of testing when a clinical audiometer and sound booth are not available.

Noise levels among spectators at an intercollegiate sporting event.

PURPOSE: The intensity of noise levels in a basketball arena during games, as well as the hearing sensitivity of attendees, was measured for the purpose of assessing the impact of the noise on hearing thresholds. METHOD: Noise levels at 10 intercollegiate basketball games were measured with a dosimeter affixed on the shoulders of attendees. Hearing thresholds and distortion product otoacoustic emissions were measured for 20 participants just before attending a basketball game and within an hour of the end of the game to determine whether changes in hearing thresholds resulted from exposure to the sound levels within the arena during the games. RESULTS: Participants demonstrated temporary shifts in pure-tone thresholds and reductions in the intensity of their otoacoustic emissions after attendance at 1 of the basketball games. Dosimeter measurements showed that noise at 6 of the 10 basketball games exceeded acceptable intensity levels when compared with a national workplace noise exposure standard. CONCLUSION: Although noise intensities, on average, did not exceed workplace exposure standards, universities would be wise to be proactive in warning spectators about the potential dangers of noise exposure at sporting events, make earplugs available to interested spectators, and implement a hearing conservation program for employees working in noise.

The effect of classroom amplification on the signal-to-noise ratio in classrooms while class is in session.

PURPOSE: The purpose of this study was to measure the signal-to-noise ratios in classrooms while class was in session and students were interacting with the teacher and each other. METHOD: Measurements of noise and reverberation were collected for 5 different classrooms in 3 different schools while class was in session. Activities taking place during the measurements were recorded to compare with sound level measures. The use of infrared classroom amplification was compared with no amplification. RESULTS/CONCLUSION: The results revealed that when classroom amplification was used, students heard the teacher's voice at a level that was an average of 13 dB above the noise floor as compared to an average of +2 dB above the noise floor without amplification.

The effect of room acoustics and sound-field amplification on word recognition performance in young adult listeners in suboptimal listening conditions.

PURPOSE: To compare the speech recognition performance of young adult listeners with normal hearing in 2 college classrooms, only 1 of which met American National Standards Institute (ANSI) S12.60-2002 acoustic standards. Also, differences in speech recognition performance were compared in both classrooms with and without the use of a classroom amplification system. The speech was presented at low intensity to simulate listening in the rear seats of a large college classroom. METHOD: Listeners were randomly assigned seats in the 2 classrooms, and Northwestern University Auditory Test No. 6 (NU-6) words were presented via a loudspeaker from the front of the classroom for all listening conditions as well as through a sound-field infrared system with ceiling-mounted speakers during the amplified condition. RESULTS: Results showed statistically significant differences in speech recognition performance between classrooms, with and without classroom amplification, and across the rows of each classroom when the classroom amplification system was not used. CONCLUSIONS: These results demonstrate how meeting the ANSI S12.60-2002 standard, which was written for elementary school classrooms, can benefit young adult listeners in postsecondary classrooms. Also, classroom amplification was shown to improve speech recognition for students across the classroom in both acoustically poor and acoustically sound classroom environments.