The two crossword solutions for the term 'Unit Measuring Loudness' are SONE and PHON. SONE is a unit of loudness that is equal to the loudness of a 1 kHz tone at 40 dB above the listener's threshold of hearing. PHON is a unit of loudness that is equal to the loudness of a 1 kHz tone at a sound pressure level of 40 dB. Both units are used to measure the loudness of sound, and are often used in audio engineering and acoustics.