# Can we measure temperature of a object just by the sound it makes?

I been thinking if temperature is a basic property of macroscopic objects rather than of quantum or microscopic objects and it is as a result of average kinetic energy of particles residing in the object either through movement of vibration.

That being said, its also described similarly in Wikipedia thus I'm sure it is a good description of temperature however this is the only description I'll use for this question but there are way more descriptions of temperature.

That however is similar to sound which is also as a result of vibration in an medium which will result in transfer due to vibrations and movement of particles being oscillated through the medium which will transfer the energy across.

That being said cant we detect a temperature just by hearing it using a detector but obviously we have to know its vital information like density of the medium and density of the material and such but not the temperature of the object

Can this be possible?

I'm in middle school so please excuse my lack of scientific knowledge therefore if any descriptions are mathematical please explain it.

• How would the object make a sound? Are you asking about the sound of dropping it - like from this awesome SE post? – jkeuhlen Jul 10 '14 at 18:24
• Do you mean that you do something like strike an object and measure the resulting frequency? Kind of like taking a tuning fork and heating it up then striking it and finding it's temperature knowing the new and original frequencies? – tpg2114 Jul 10 '14 at 22:04
• I mean that leaving the object inside a sound frequency detector which will measure any sort of particles bouncing as a result of heat and this particles will behave like sound and be heard by the detector – LogicProgrammer Jul 10 '14 at 22:06
• A related note: if your shower spray hits your shower curtain, then you can hear the impact sound change as the water warms up. – Daniel Griscom Sep 12 '15 at 0:57

This page gives a chart of Young's modulus over temperature for various metals. Taking the top line of the table, the modulus drops from 31.4 Msi at -325F (-200C) to 24.2 Msi at 800F (427C). Due to thermal expansion, you will have more square inches. Using a linear expansion of $12E-6 K^{-1}$ the area of a bar will increase $1.5\%$ The longitudinal frequency will then drop from $1$ to $\sqrt{\frac {24.2}{31.4}\cdot 1.015} \approx 0.88$ over that range. It isn't very sensitive, but you can get some indication.