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).
Joyce
Joyce is now well below its former popularity. All-time it's been given to 512,232 U.S. babies, the 1,555th most common name by sound today, peaking at 16,807 in 1942, with 233 in 2025.
Joyce has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).