Frequency is plotted along the x-axis and sound level is plotted on the y-axis. This frequency plot and ones like it are sometimes called equal loudness contoursor Fletcher-Munson curves(after the researchers who did groundbreaking research on the perception of loudness). The figure at the right (taken from ) shows the typical frequency response of the human ear. For best results, you will need good quality over-the-ear headphones. To see how it’s done, take your own hearing test using the tool on the “Music Acoustics” website at the University of New South Wales. The listener compares tones at different frequencies and is asked to adjust the amplitude of one of the tones until the two tones sound equally loud. Hearing tests can be used to construct equal loudness contours. Our ears are far less efficient at frequencies outside this band. This is fortunate- most human speech takes place in this frequency band. Our ears are especially sensitive to sounds with frequencies between 300 Hz to 3000 Hz. (For most people, the 1000 Hz version will seem much louder). However, frequency also plays a role in loudness perception- a 70 dB tone at 1000 Hz and a 70 dB tone at 16,000 Hz will not be perceived as equally loud, even though the intensities are the same.
![equal loudness and hl decibel scale equal loudness and hl decibel scale](https://aquietrefuge.com/wp-content/uploads/2018/11/decibel_infographic_featured.png)
If a sound is played at 50 dB and then the same sound is played at 70 dB, our brains interpret the 70 dB sound as louder. Loudness perception 44 Frequency and loudness perception Loudness perception (and frequency)Īmplitude plays the dominant role in loudness perception.