The foundational call of the shofar is a summons from spiritual sleep: Rambam, Hilchot Teshuvah 3:4 states that although the shofar-blast is a scriptural decree, it carries a hint — 'awaken, O sleepers, from your slumber, and you who slumber, arise from your torpor; examine your deeds and return in repentance, and remember your Creator' — addressed to those who forget the truth in the vanities of time and wander all their years in emptiness, and Kitzur Shulchan Arukh Yalkut Yosef, Orach Chaim 589:11 transmits the same call in nearly identical language, confirming its centrality as the shofar's inner meaning.
The Sefer HaChinukh explains that because the human being is corporeal and is not aroused to action without an external stimulus — just as warriors cry out at the moment of battle to rouse themselves — so on Rosh Hashanah, the day designated from of old to judge all who enter the world, each person must awaken his nature to seek mercy for his sins, and the voice of the shofar powerfully stirs the heart of all who hear it (Sefer HaChinukh, Mitzvah 405).
The broken, wailing character of the teruah sound is itself the inner substance of what the shofar accomplishes: the Gemara establishes that the biblical term yevava — derived from the wailing of Sisera's mother — is the model for the shofar's cry, and the dispute between moaning broken sighs (shevarim) and whimpering wails (teruah) reflects two ways of understanding that primal broken sound (Rosh Hashanah 33b), while Likutei Halakhot, Orach Chaim, Laws of the New Year 4:5:2 identifies shevarim-teruah specifically as the aspect of shame and a broken heart — the groaning and wailing that arise from shame over one's transgressions — and names this shame the very core of the shofar's voice, which is comprised of many colors, because through shame one merits the glory that encompasses all those colors.
The broken sounds lead toward a restored, expanded awareness: Likutei Halakhot, Orach Chaim, Laws of the New Year 3:2:1 teaches that through the shevarim-teruah, which are the aspect of teshuvah, a person merits additional understanding of the Creator's greatness, so that the final tekiah draws the higher consciousness inward — and for this reason the entire world is stirred to teshuvah at the moment of shofar-blowing, since this is the shofar's essential purpose.
Sefat Emet, Devarim, Shabbat Shuva 21:4 reads the verse 'happy is the nation that knows the teruah' (Tehillim 47:2) through the Zohar's explanation that 'knows the teruah' means they shatter their hearts through it, and that through this heart-shattering all the forces of judgment are likewise shattered and nullified — a direct link between the broken voice, the broken heart, and the breaking of harsh judgment.
Sefat Emet, Devarim, Rosh HaShanah 19:4 develops this further, teaching that 'the voice is the voice of Yaakov' and that through sin the inner voice becomes twisted and broken, yet through teshuvah the broken sounds of shevarim-teruah in the middle are absorbed and dissolved back into the straight, simple tekiah that precedes and follows — so the shofar's sequence enacts the rectification of the soul's distorted voice into wholeness.
The shofar's voice carries an aspect of gevurot — powerful divine force — that strikes the mind: Likutei Moharan 5:3 teaches that the shofar's sound, associated with the ram of Yitzchak and with 'the thunder of His gevurot,' hits the mind in the manner of thunder from rain-clouds, so that one who hears it blown by a God-fearing person need have no fear of thunder the entire year, and the shofar's blast is the very mode through which the divine appeared to Israel.
At the level of divine names and attributes, the shofar-blast effects a movement from the attribute of strict judgment to the attribute of mercy: Kedushat Levi, Devarim, For Rosh HaShanah:34 reads the verse 'Elohim ascends with the teruah, the Lord with the shofar-blast' (Tehillim 47:6) as signifying that the name Elohim — which points to strict judgment — rises upward, and at the moment of shofar-blowing it is called by the name of the Lord, which points to compassion, drawing on the teaching of the Tikkunim that when Israel sounds the shofar, the Holy One moves from the throne of judgment to the throne of mercy; the Kedushat Levi further illustrates that Israel, like beloved servants before a great king, requests its needs only through the wordless hint of the teruah rather than through explicit speech, and the King fulfills the request.
The Zohar, as explained by Sulam on Zohar, Vayera 381:1, likewise teaches that on Rosh Hashanah and Yom Kippur, when judgment is present in the world and the adversary stands to accuse, Israel must rouse itself with the shofar and sound a voice that encompasses water, fire, and wind — the three qualities of Chesed, Gevurah, and Tiferet — unified within it, so that the integrated voice emerges from the shofar as a single whole.
Bnei Yissaschar, Tishrei 2:1 notes that Rosh Hashanah is the day of judgment and Gevurah, and that the numerical structure of the day — ten instances of the divine name Elohim corresponding to the measure of that attribute — points to the cosmic weight of the occasion on which the world is judged, while Bnei Yissaschar, Tishrei 2:4 adds that the righteous one's arguments on behalf of Israel before the divine court on this day of judgment are preserved whole, with none of his pleading-points broken or repelled.