How to read the band →
Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Ethel
Ethel was a common American name in the 1910s but is rarely given today. It's been given to 280,412 U.S. babies all time and once ranked 65th by sound, peaking at 8,110 in 1918 (down to 34 in 2025).
Ethel has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).