Binaural Loudness Summation
Epstein and Florentine (2009) presented monitored live voice (MLV) spondees, recorded spondees, and pure tones (1000 Hz, pulsed, 200 msec) monaurally and binaurally via loudspeakers and earphones to eight normal hearing young listeners (aged 19 to 30 years; 5 female, 3 male). Binaural loudness summation was determined to be less for loudspeakers than for earphones and, binaural loudness summation was noted to be least with MLV spondee presentation via loudspeakers. With regard to their data, and previous data (Whilby et all, 2006, Cox and Gray 2001), Epstein and Florentine recommend that loudness assessment for binaurally fitted hearing aids should be verified using realistic stimuli via loudspeakers.
For More Information, References and Recommendations:
Cpc, RM., Gray, GA (2001): Verifying Loudness Perception After Hearing Aid Fitting. American Journal of Audiology, 10, Pages 91-98.
Epstein, M. and Florentien, M. (2009): Binaural Loudness Summation For Speech and Tones Presented Via Earphone and Loudspeakers. Ear & Hearing. Vol 30, No 2, Pages 234-237.
Whilby, S., Florentine, M., Wagner, E., et al (2006): Monaural and Binaural Loudness of 5 and 200 msec Tones in Normal and Impaired Hearing. JASA, 119, pages 3921-3939.