Jens Blauert completed a lot of studies into localisation of sound from the late 1960’s on for several decades. In one of his key studies, he found that certain frequency bands give the impression of coming from particular directions for listeners. This study was based on sending 1/3 octave pulses of noise to listeners over headphones. There is a good summary including a graph of the frequencies that you can check out at:
http://science-of-sound.net/2016/01/about-jens-sound-localization-in-the-median-plane/
You can also download a copy of Blauert’s 1969 paper Sound Localization In The Median Plane from:
https://www.researchgate.net/publication/263716618_Sound_Localization_in_the_Median_Plane