I cannot answer for pointed ears specifically, but the shape of ears is known, in audio science, to have an impact on sounds reflected into the ear canal.
See here, an excerpt is below (The pinna is the outer part of the ear; plural is pinnae):
In animals the function of the pinna is to collect sound, and perform spectral transformations to incoming sounds which enable the process of vertical localization to take place. It collects sound by acting as a funnel, amplifying the sound and directing it to the auditory canal. While reflecting from the pinna, sound also goes through a filtering process, as well as frequency dependent amplitude modulation which adds directional information to the sound (see sound localization, vertical sound localization, head-related transfer function, pinna notch). In various species, the pinna can also signal mood and radiate heat.
In humans at least (because it is easier for us to tell researchers what we are hearing) if the outer folds, bumps and valleys of our pinnae are filled with wax, even if no wax is used close to the ear canal, we lose the ability to locate the source of sounds. These folds, bumps and valleys are unique to each person, but when simulated on a computer they create micro-echoes and amplifications that are dependent upon the location of sounds; and the hypothesis is that our brains learn to interpret these in order to give us a sense of sound source position.
Thus, the pointing of the elven ears, whether movable or not, may be useful to them in triangulating sound sources; perhaps higher or lower frequency sounds than in the human range. Many animals with pointed ears do hear frequencies well above the human range. The point of the pointing (ha!) may also just be the physical length afforded; when it comes to sound waves this scale of difference can matter: It is why our bass speakers [and bass musical instruments] have to be larger than other speakers [and musical instruments], for example. The point may act as a wave guide for high frequencies that amplifies them in the elven ear canal.