No definitions found for 'upper frequencies'
Perhaps one of these:
upper paleolithic,
upper fruitland, nm,
upper black eddy,
upper fruitland,
upriver,
upper brookville, ny,
upper avon river,
upper pharyngeals,
upper avon,
upper brookville,
upper providence township,
upper bench,
upprop,
upper berth,
upper peninsula,
upper bound,
upper balcony,
upper falls,
upper volta,
upperville,
upper providence township, pa