Loudness lacked any measurement tool or unit until Stevens invented both.

Evidence

At the time Stevens was conducting his research, there were no psychophysical tools available to measure the loudness of sounds. Consider the difficulty he faced: How would you measure sound pressure level if you didn’t have a sound level meter, your weight without a scale, or length without a ruler? Not only did Stevens not have any tools to measure loudness, there was no unit for loudness either. Consider again the implications of not having a measurement unit: How would you quantify sound pressure level without the pascal, your weight without pounds, or length without inches? In his impressive body of work, Stevens developed both the measurement tools to quantify loudness as well as a unit that allowed the quantification of loudness. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 707

Categorization

Category: Factual Claims

• DEFINE: Establishes the historical context that loudness measurement is a constructed, invented endeavor rather than something naturally given.

Related

• Stevens had to invent both the tools and the unit for measuring loudness (similarity 0.96)
• No single frequency-weighting can accurately meter loudness at all levels (similarity 0.84)
• Stevens defined one sone as a 40 dB SPL 1000-Hz tone (similarity 0.84)
• Loudness is not reducible to sound pressure level or signal power (similarity 0.84)
• Sound level meters measure pressure, from which intensity is derived (similarity 0.84)
• Loudness as perception can never be directly measured physiologically (similarity 0.83)
• Loudness evaluation may be unchanged by obscuring the sound’s source identity (similarity 0.83)
• Loudness is a psychological percept measurable only through human report (similarity 0.82)
• Stevens anchored the sone unit to a 1000-Hz tone at 40 dB SPL. (similarity 0.82)
• Barkhausen created the loudness level measure in the 1920s (similarity 0.82)
• Loudness is measured psycho-acoustically via magnitude estimation against a reference (similarity 0.82)
• Lack of intensity-measuring instruments shaped early psychoacoustic research priorities (similarity 0.81)
• A-weighted sound power ratios overestimate perceived loudness differences in noise emissions. (similarity 0.81)
• Loudness models estimate total neural activity since it cannot be measured directly (similarity 0.80)
• Fletcher originated threshold measurement, loudness relations, and masking models (similarity 0.80)