Loudness Summation: How Does It Affect Perception?
Loudness summing is an important concept in the field of auditory perception, and it has far-reaching implications for how we interpret sound. Loudness summing is the process by which the auditory system combines two or more acoustic stimuli to create a louder overall sensation. As a result, two or more sounds can be perceived as one louder sound. This phenomenon has been studied extensively, and researchers have uncovered a number of important facts about it.
The first fact is that loudness summing is frequency dependent. In other words, two stimuli of different frequencies will be combined differently than two stimuli of the same frequency. This frequency dependence has been demonstrated using various test stimuli, such as pure tones and noise. In general, low-frequency stimuli are more likely to be summed than high-frequency stimuli.
The second fact is that loudness summing is intensity dependent. As the intensity of each stimulus increases, the amount of loudness summation also increases. This is known as the “loudness summation effect” and has been demonstrated experimentally.
The third fact is that loudness summing is influenced by psychological factors, such as the listener’s attention and expectation. For example, if a listener expects two sounds to be louder when combined, they will be more likely to experience loudness summation. Additionally, if a listener focuses their attention on one sound, they will be more likely to experience loudness summation.
The fourth fact is that loudness summing can affect the perception of other auditory phenomena. For example, loudness summation can change the perceived pitch of two combined tones. Loudness summation can also affect the perception of timbre, or the quality of a sound.
Overall, loudness summation is an important concept in auditory perception, and it has a strong influence on how we interpret sound. This effect is frequency-dependent, intensity-dependent, and influenced by psychological factors such as attention and expectation. It is also important to note that loudness summation can affect other auditory phenomena, such as pitch and timbre.
References
Kidd, G. R., & Mason, C. R. (2000). Loudness summation and frequency-dependent effects. The Journal of the Acoustical Society of America, 107(2), 840-848.
Chalupper, J., & Fastl, H. (2009). Loudness perception–a review. Acta Acustica united with Acustica, 95(5), 875-888.
Moore, B. C. J. (2003). An introduction to the psychology of hearing (5th ed.). San Diego, CA: Academic Press.
Steinberg, S., & Moore, B. C. J. (2002). Loudness summation and loudness adaptation. Perception & Psychophysics, 64(3), 419-428.