by Reb Aharon Rubin, from Eye to the Infinite, shared with permission.
Theory and Technique
The sages list ten types of prayer. Each type corresponds to one of the Sefiroth, expressing a different aspect of the soul and affecting the cosmos in its particular way. However, all prayer involves the articulation of desire, thought and emotion (corresponding to the three moichin: Chochmoh (thought), Binoh (emotion) and Kether (desire).) When desire, thought and emotion are combined with speech, they have the power to affect the supernal worlds.
“Desire”, the soul’s longing to attach on high, corresponds to the World of Atsiluth, the highest world. But longing is not enough. To draw the unity of one’s attachment to G-d further down, into the worlds of Bri’oh and Yetsiroh, desire needs to be translated into thought and emotion – focusing thought and desire, through the words of prayer. Finally, it must be expressed. Vocalising desire, thoughts and emotions, provides an anchor for the heavenly influx in the world of Assiyoh. Thus, blessing is manifest throughout.
Vocal enunciation also focuses the mind. The brain hears the thoughts expressed, causing it to continue those thoughts and emotions. The circle is repeated, increasing in depth and momentum, keeping mind and heart unified.
Additionally, the Chassidic mystics teach that the voice has the power to lift a person out of the depths to the uppermost spiritual heights. Thus, how you say the words, reflecting content and your awareness in your voice, is extremely important. Today, we can measure the affect words spoken with emotional intent have on the neurological system; they affect heartbeat, respiration and brain waves. This symbiosis is an indication of prayer’s unifying effects in the higher realms.
Prayer thus unifies the inner psyche.
 Pesochim 117a, Devorim Rabboh 2. Tiqunei Zohar, Tiqun 13. (See also Yalkut Shim’oni, Deut. 3, para. §811, who lists thirteen. This is not a contradiction: the ten categories are further expressed by the thirteen [see Chapter 3].)
 The Toldoth Yaakov Yosef explains, in the name of the Ba’al Shem Tov, that this causes unification of the three moichin, Kether, Chochmoh and Binoh, with the Sefiroh of Malchuth.
 See Ba’al HaTurim Genesis 28:12 and Zera Qodesh ad loc. The Hebrew word קול – qol (voice) has the same numeric value as סולם – sulom (ladder). It also starts with the letter quf ק that reaches downward and ends with the lamud ל that reaches upwards. This depicts the qualities of the voice and music: they address the lowest level and can elevate to the highest. Cf. Nefesh HaChaim, Gate 2, Chap. 10.
 See Liqutei MoHaRan, 5:3.