- Abstract The temperature dependence of the sound velocity in liquid lead, tin, bismuth and antimony has been measured with high precision (errors of less than 0.35%) by the ultrasonic pulse transmission technique. The measurements were performed from the melting temperature to approximately 1000° C. A smooth temperature dependence of the sound velocity was found in liquid lead and antimony. In liquid lead, a linear dependence with a negative temperature coefficient was observed whereas for liquid antimony the sound velocity displays a distinct maximum. The high precision of the measurements enabled uncovering localized features in the temperature dependence of the sound velocity in liquid tin and bismuth. The measurements provide some information on the temperature dependent structure of the molten state of these four elements.