Our Gemara on amud beis tells us that a source for understanding what the Teruah blow of the Shofar sounds like comes from Sisera’s mother’s wailing:

אָמַר אַבָּיֵי: בְּהָא וַדַּאי פְּלִיגִי, דִּכְתִיב: ״יוֹם תְּרוּעָה יִהְיֶה לָכֶם״, וּמְתַרְגְּמִינַן: ״יוֹם יַבָּבָא יְהֵא לְכוֹן״. וּכְתִיב בְּאִימֵּיהּ דְּסִיסְרָא: ״בְּעַד הַחַלּוֹן נִשְׁקְפָה וַתְּיַבֵּב אֵם סִיסְרָא״. מָר סָבַר גַּנּוֹחֵי גַּנַּח. וּמָר סָבַר יַלּוֹלֵי יַלֵּיל.

Abaye said: In this matter, the tanna’im certainly disagree. Although the first baraita can be reconciled with the mishna, this second baraita clearly reflects a dispute. As it is written: “It is a day of sounding [terua] the shofar to you” (Numbers 29:1), and we translate this verse in Aramaic as: It is a day of yevava to you. And to define a yevava, the Gemara quotes a verse that is written about the mother of Sisera: “Through the window she looked forth and wailed [vateyabev], the mother of Sisera” (Judges 5:28). One Sage, the tanna of the baraita, holds that this means moanings, broken sighs, as in the blasts called shevarim. And one Sage, the tanna of the mishna, holds that it means whimpers, as in the short blasts called teruot.

Even the evil general Sisera still had a mother.  Like all mothers, even the mothers evil people worry about their kids.  When Sisera’s mother found out he was killed, she sobbed and wailed inconsolably. This kind of cry is akin to the Teruah noise of the Shofar. 

I must pause for a moment and share a few interesting stories about this.  My father ZTL was a prison chaplain at the Atlanta Federal Penitentiary.  The famous gangster Mickey Cohen was beaten up within an inch of his life.  When my father visited him, he described him as covered from head to toe in casts and bandages.  He said, “Rabbi, tell my Mom, I am ok.”  Whenever my father would tell this story he would start to cry, and then go on to explain how Mickey sent his machine gunner, “Chopsie” to Israel in order to help teach the Irgun how to fire automatic weapons.

This is reminiscent of the Gemara Berachos (57a)

אֲפִילּוּ רֵיקָנִין שֶׁבָּךְ, מְלֵאִים מִצְוֹת כְּרִמּוֹן 

Even the most empty [reikanin] among you, Israel, are full of mitzvot like a pomegranate.

Some of you New Yorkers may remember the infamous Joel Steinberg, who was imprisoned for beating his six year old daughter Lisa Steinberg.  I remember as a child, his mother said in one interview, “He is a good boy - he writes to me every day.”

This is a Jewish mother. But I digress. Back to Sisera and the Shofar.  Years ago as a bochur, I heard Rav Moshe Weinberger explain the idea as follows.  Sisera’s mother kept looking out the window to see when her son would return from battle.  As time passed, she became more nervous, but her friends comforted her by saying, “He is probably just delayed because of all the spoils and riches he is gathering.”  (Shoftim 5:28-29) When she finally finds out he is dead, something that deep down she suspected all along, her hopes and rationalizations were shattered.  This was her deep cry and this is the shofar, representing our deep cries, knowing we are out of excuses.

I heard a similar idea from Rav Menachem Genack in the name of Rav Soloveitchik.  We read from the story of Chana on Rosh Hashana because of her heartfelt prayers which came about from a sense that she must throw herself fully at God’s mercy.  The Rav’s interpretation of the story was that when Elkanah told her “Hannah, why are you crying and why aren’t you eating? Why are you so sad? Am I not more devoted to you than ten sons?”  (I:Shmuel 1:8) this did the opposite of comforting her.  She suddenly realized that Elkana gave up.  Perhaps in the back of her mind she was counting on Elkana’s prayers.  But now all her rationalizations were shattered. She hit rock bottom and knew it was only up to her and God.  That is when her prayers went into overdrive.