Distortion product otoacoustic emissions in school children: Effects to gender, ear asymmetry and handedness

Accurate interpretation of distortion product otoacoustic emission (DPOAE) data cannot be made without realizing the effects of non-pathological factors on DPOAEs. The present study aimed to examine the effects of ear asymmetry, gender and handedness on DPOAEs obtained from school children. One thousand and three children (528 boys and 475 girls) with a mean age of 6.2 years (SD = 0.4, range = 5.2 7.9 years) were tested in a quiet room at their schools using the GSI-60 DPOAE system. The stimuli consisted of two pure tones of different frequencies f1 and f2 presented at 65 and 55dB SPL respectively. A DP-gram was obtained for each ear with f2 varying from 1.1 to 6.0 kHz and the ratio of f2/f1 being kept at 1.21. The signal-to-noise ratios (SNR) (DPOAE amplitude minus the mean noise floor) at the tested frequencies 1.1, 1.5, 1.9, 2.4, 3.0, 3.8, 4.8, and 6.0 kHz were measured. The results revealed a small, but significant difference in SNR between ears, with right ears showing a higher mean SNR than left ears at 1.9, 3.0, 3.8 and 6.0 kHz. At these frequencies, the difference in mean SNR between ears was less than 1 dB. A significant gender effect was also found, with girls exhibiting a higher SNR than boys at 3.8, 4.8 and 6.0 kHz. The difference in mean SNR, as a result of the gender effect, was about 1 to 2 dB at these frequencies. The results from the present study indicated no significant difference in mean SNR between left-handed and right-handed children for all tested frequencies. In conclusion, these non-pathological characteristics of DPOAEs should be considered in the interpretation of DPOAE results for school children.

Proceedings of the 2004 Australian Software Engineering Conference

Established in 1986, ASWEC is the premier technical meeting for the Australian Software Engineering Community, and attracts a significant number of international participants. The conference is sponsored by both Engineers Australia and the Australian Computer Society. The major goal of the conference is to provide a forum for exchanging experience and new research results in software engineering. The technical program for ASWEC 2004 includes research papers from Australia and across the world. This year we received 79 submissions from 12 countries: 56 from Australia, 6 from New Zealand, 9 from Asia, 4 from Europe, and 4 from North America. All papers were fully refereed by three (two papers by only two) Program Committee members. We accepted 36 papers to be presented at the conference. We are grateful to all authors who contributed to ASWEC 2004. In addition to the technical papers, the conference program also includes two keynote speakers and one panel on Software Engineering accreditation. We are very pleased about being able to attract Philippe Kruchten, University of British Columbia, and Ian Hayes, The University of Queensland, as the keynote speakers for this conference.