Speed of sound in a gas depends on temperature and molecular weight, not pressure

Evidence

Equation 1.5 is important because it shows that the speed of sound in a gas is not affected by pressure. Instead, the speed of sound is strongly affected by the absolute temperature and the molecular weight of the gas. Thus we would expect the speed of sound in a light gas, such as helium, to be faster than that in a heavy gas, such as carbon dioxide, and, in air, to be somewhere in between. — David Howard, Jamie Angus, coustics and Psychoacoustics, 61

Equation 1.5 is important because it shows that the speed of sound in a gas is not affected by pressure. Instead, the speed of sound is strongly affected by the absolute temperature and the molecular weight of the gas. Thus we would expect the speed of sound in a light gas, such as helium, to be faster than that in a heavy gas, such as carbon dioxide, and, in air, to be somewhere in between. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 84

Categorization

• QUESTION: Counterintuitive that pressure doesn’t affect sound speed in a gas — worth holding onto as a conceptual anchor against intuition.
• DEFINE: Establishes the fundamental determinants of sound speed in gases, correcting the intuitive assumption that pressure matters.
• corroborated: 7 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 61; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 84
• XREF: connects to: Speed of sound depends on temperature, not pressure; Lower temperature slows the speed of sound predictably via thermal molecular motion; Sound speed in air varies only with the square root of absolute temperature — David Howard, Jamie Angus, coustics and Psychoacoustics, 65 (+3 more)

Broader Connections

• Sound speed in air varies only with the square root of absolute temperature #qualifies (0.85) — David Howard, Jamie Angus, coustics and Psychoacoustics, 65
• Air’s speed of sound varies only with the square root of absolute temperature. #qualifies (0.85)
• Humid air carries sound faster than dry air because water molecules are lighter #exemplifies (0.80)
• A medium’s intrinsic acoustic impedance equals density times sound speed #expands (0.72) — Eric J. Heller, Why You Hear What You Hear- An…, 102