Take Quiz Exit 80 75 O 70 65 Comparison Level (dB SPL) 60 55 50 45 100 200 400 800 1000 1600 3200 6400 Comparison Frequency (Hz) Figure 1 Figure 1 shows two equal loudness contours measured for a standard 1000-Hz tone at 50 dB SPL (triangles) and 70 dB SPL (circles), respectively. What level in dB SPL is required for a 400-Hz tone to have a 50-phon loudness? What level in dB SPL is required for a 100-Hz tone to have a 50-phon loudness? What level in dB SPL is required for a 400-Hz tone to have a 70-phon loudness