Introduction
¿ Before you start ¿
Before you start, please consider that not all languages are the same, nor do they have the exact same meanings for all words. In fact, there are words in other languages which have no English equivalent.
What does Shiva mean?
While "Shiva" is represented in the Male Gender, it is importaht to note that Shiva per se has no genitals since Shiva is not a physical person.
Shiva - part of the Trimurti - has many meanings including without Death, Timeless, Formless, Auspicious, Benevolent and Everywhere.
What is interesting is that Shiva is more commonly known as the "aspect" of destruction - this creates a conundrum with the word "Benevolent" above unless you also see Shiva as the "attribute" of Cosmic Reincarnation.
Shiva symbolizes pure consciousness and the destruction of ego, allowing for spiritual regeneration.
The "hint" is that when people become egotistical - they are destroyed because they do NOT fulfill the design of creation.
The reason that you see the "without death" and then "the destroyer" as confusing, is because you are very simplistic in your thought process and you think that lineal physicality is all that there is.
The point of Creation, is not to satisfy you or your personal whims and desires.
In this aspect, Shiva represents the catalyst for cosmic reincarnation.
Below
Below it says Shivo Hum which is commonly translated as "I am Shiva".
There are (at least) 4 interpretations to these words.
- 1) "I am Shiva" may be said from the "Sages" perspective where he has united** with one of the attributes of The Creator and is attempting to describe the union.
- 2) "I am Shiva" may also be interpreted as how The Creator would be described in the first person human level. (anthropomorphically speaking)
- 3) The 3rd interpretation is a bit beyond most people to comprehend. According to Hindu tradition + scriptural commentaries, and also Smarta tradition (Smartism / Smartaism), Adi Shankara (Adi Shankaracharya) is considered an avatar or incarnation of Lord Shiva.
- 4) If you understood the monumental magnitude of the sage "Adi Shankara", you would realize that he is NOT describing "himself" as Shiva (per se) even though he may represent Shiva in avatar form.
⩺ Instead he is merely the "conduit" through which the words are manifested in such a way that they may be understood by even the simplest of people (at that time).
⩺ Just as copper or gold are not electricity, yet they allow the agitation of electrons and thus the transference of electricity because of the purity of their specific structure **. 
Due to the loss of electricity between Point A and Point B, you need to have "Sub-stations"
which utilize Step-Up "Transformers"
.
This is where humans come into the picture. When their minds and bodies are pure enough, they are "potentially" capable of being a conduit for the Divine Golden Influx (The Sh'far) from above.
This "Sh'far" (שְׁפַר) is described as being annointed on your forehead by warm oil. (BTW: what you read on google / bing etc regarding the Sh'far is mostly not correct in the above context.)
This is a pure energy from "above" and it is also sometimes described as being immersed in esoteric honey.
This is the purpose of keeping Kosher.
IF you Eat the wrong foods then you will absorb bad energy.
But eat the right foods, in the correct "order" - then you can attune your physical body to higher frequencies.
This is why Hinduism and Buddhism encourage vegetarianism as a form of non-violence (ahimsa अहिंसा) form of eating.
Ahimsa is a foundational virtue in Hinduism, Buddhism, and Jainism.
Back to the story.
The following information would be (IMO) from the Sage's perspective as he attempts to describe The Creator or as the (restricted) light from The Creator flows through him expressing itself in physical words.
Think of it like this, if you were asked to describe an airplane to someone 1,000 year ago, - using words only - you could articulate roughly what a plane looks like, but this does not mean that you "are" the plane.
Plus you have to assume that the listener understands what wings, engines, wheels and fuselage (etc) are.
Then you have to contend with the possibility that they may not believe you - and then you have those - who are completely in their animal soul and - who simply get angry because their brain hurts or for religious reasons.
The essence of this phrase is that I dwell "with" Shiva and I have become "At One" with The Creator - which Shiva represents in Vedic literature.
This is an assumptive guess - as explained by my teacher - since we are unable to personally ask the Sage. There is a much deeper explanation for those who are more advanced.
It is generally "a given" that The Creator cannot be described by any human concepts, thus it may also be possible that this interpretation was given "through" Adi Shankara by one of the "Attributes" of The Creator involved in the creation of our Universe as a way of expressing the infinite in a finite way that even a simple mind may be able to grasp. (These levels are described here "God Frequency"
) back to Before You Start. 
Judaeo-Christian Teachings ↟↟
Please consider "Psalm 27:4"
if you really want to know the answer to this question. In Psalm 27:4 it basically says the same thing but uses different words.
"One (thing) I ask of the Lord, I seek that I may dwell in the house of the Lord all the days of my life, to see the pleasantness of the Lord and to visit His Temple every morning." (common translation)
"Psalm 27:4"
intimates that the speaker is "at One" with The Creator by dwelling "in" the "temple" of The Lord all the days of their life. The real spin out in this is the B'Noam-Adonai בְּנֹֽעַם-יְ֜הֹוָ֗ה or במען-יהוה.
The thing that most Westerners are unaware of is that in most older "religions", there are written texts "PLUS" an oral teachings. In some "religions", the written texts have been lost or completely forgotten and they are simply left with the oral teachings.
And then you have corruptions on the original language by translations.
An expanded example of different words meaning the same thing in different languages (1 example) would be the word Thank You in English.
In Spanish it is Gracias, in French it is Merci, in Farsi it is Mersi, in Tagalog it is Salamat, in Arabic it is Shukran, in Russian it is Spasebo (often pronounced as spaseba), in Sanskrit it is Dhanyavaadaha (धन्यवादः ) etc etc.
My point is that all of these words mean the same thing. They are just vocalized differently. It is up to the student (you) to learn the direct and indirect and even slang interpretations of words and any direct or implied associations with other words etc.
I Am - I Am Not ↟↟
The "I Am" and the "I Am Not" have been added in most cases to grammatically Anglicize the text.
Similar to Japanese, when the "person" is talking about themselves, they rarely use the word "I" (watashi - 私) to define themselves in a sentence. 「watashi is not the only word used to define "I" in Japanese - you also have Boku and Ore + you also have visual queues.」
The Author ↟↟
The Nirvana-Shatakam (Nirvāṇa-ṣatkam निर्वाणषट्कम्), is a composition attributed to the Hindu sage Adi Shankara.
Wordless Song ↟↟
On a physical level, this Nirvana-Shatakam Mantra is so beautiful because it strips away all of human "vices" and stupidity.
It reveals (IMO) a true essence we may aspire to attain in our lives. It removes the clouds of flesh and reveals the Sun in all of its magnificent splendor on a level most people can comprehend.
The only thing I have encountered which is higher than this captivating prose is the Wordless Song. This is something I wish you all to experience one day when you learn to Open your heart to the source of Creation.
Final Thought ↟↟
Did you know that if you say something without conviction (not genuine), that the words have a different resonant energy, than if you say the same word or words with conviction and a pure heart.
You are a child of the Universe and no less than the trees and the stars, you have a right to be here.

Preamble ↟↟
- Vital Life Energy (Prana)
- The Five Vital Airs (manifestations of Prana)
- Conscious bliss (God level Love)
- Shiva (Represents what most people call The Creator in the same way that we call The Creator "God")
- Shivo'ham (Represents unity with The Creator and not that "I" am god) This may also be interpreted as "I am One with The Creator".
Nirvana Shatakam Lyrics
Click here to listen to the "Nirvana Shatakam Mantra"
or this more energetic version of "Nirvana Shatakam" 
English Transliteration
1)* Māṇo buddhi ahankara chittani nāhaṃ
na cha shrotravjihve na cha ghraana netre
na cha vyoma bhumir na tejo na vaayuhu
* chidananda rupah shivo-ham shivo-ham
2) Na cha prana sangyo No vai pancha vayuhu
No va sapta dhatur No va pancha koshah
No vak pani-padam No chopastha payu
chidananda rupah shivo-ham shivo-ham
3) Na me dvesha ragau na me lobha mohau
na me vai mado naiva matsarya bhavaha
na dharmo na chartho na kamo na moksha
chidananda rupah shivo-ham shivo-ham
4) Na punyam na papam na saukhyam na duhkham
na mantro na tirtham na veda na yajnah
aham bhojanam naiva bhojyam na bhokta
chidananda rupah shivo-ham shivo-ham
5) Na me mrtyu shanka na mejati bhedaha
pita naiva me naiva mataa na janmaha
na bandhur na mitram gurur naiva shishyaha
chidananda rupah shivo-ham shivo-ham
6) Aham nirvikalpo nirakara rupo
vibhut vatcha sarvatra sarvendriyanam
na cha sangatham naiva muktir na meyaha
chidananda rupah shivo-ham shivo-ham
English
Not mind, nor intellect or ego,
Not the organs of hearing, tasting, smelling or seeing,
Not space, Not earth, Not fire, Not air,
I am *conscious bliss, I am (One with) *Shiva, I am (One with) Shiva.
No *Vital Life Energy, not the *Five Vital Airs,
Not the seven essential ingredients, not the 5 sheaths of the body,
No body parts, No physicality
I am conscious bliss, I am (One with) Shiva, I am (One with) Shiva.
No hatred, No passion, No greed nor delusion,
No pride, nor jealousy in me,
Not identified with duty, No wealth, No lust or liberation,
I am conscious bliss, I am (One with) Shiva, I am (One with) Shiva.
No virtue, No vice, No pleasure, No pain,
No mantras, No pilgrimage, No scriptures, No rituals,
Not the experience, not the object of experience, not the one who experiences,
I am conscious bliss, I am (One with) Shiva, I am (One with) Shiva.
Not bound by death and its fear, No caste or creed,
No father, nor mother, No birth,
No relative, No friend, No teacher No student,
I am conscious bliss, I am (One with) Shiva, I am (One with) Shiva.
I am devoid of duality and I am formless,
I am omnipresent, I exist everywhere, pervading all senses,
No attachment, neither free nor limited,
I am conscious bliss, I am (One with) Shiva, I am (One with) Shiva.
Sanskrit
मनोबुद्ध्यहङ्कार चित्तानि नाहं
न च श्रोत्रजिह्वे न च घ्राणनेत्रे ।
न च व्योम भूमिर्न तेजो न वायुः
चिदानन्दरूपः शिवोऽहम् शिवोऽहम् ॥१॥
न च प्राणसंज्ञो न वै पञ्चवायुः
न वा सप्तधातुः न वा पञ्चकोशः ।
न वाक्पाणिपादं न चोपस्थपायु
चिदानन्दरूपः शिवोऽहम् शिवोऽहम् ॥२॥
न मे द्वेषरागौ न मे लोभमोहौ
मदो नैव मे नैव मात्सर्यभावः ।
न धर्मो न चार्थो न कामो न मोक्षः
चिदानन्दरूपः शिवोऽहम् शिवोऽहम् ॥३॥
न पुण्यं न पापं न सौख्यं न दुःखं
न मन्त्रो न तीर्थं न वेदा न यज्ञाः ।
अहं भोजनं नैव भोज्यं न भोक्ता
चिदानन्दरूपः शिवोऽहम् शिवोऽहम् ॥४॥
न मृत्युर्न शङ्का न मे जातिभेदः
पिता नैव मे नैव माता न जन्मः ।
न बन्धुर्न मित्रं गुरुर्नैव शिष्यं
चिदानन्दरूपः शिवोऽहम् शिवोऽहम् ॥५॥
अहं निर्विकल्पो निराकाररूपो
विभुत्वाच्च सर्वत्र सर्वेन्द्रियाणाम् ।
न चासङ्गतं नैव मुक्तिर्न मेयः
चिदानन्दरूपः शिवोऽहम् शिवोऽहम् ॥६॥
The Gamma Wave Version
There are 5 main wave groups (so far) and some are sub-divided like the Alpha group.
- Gamma
- Alpha
- Beta
- Theta
- Delta
Whomever named these did not understand the Greek alphabet. 
These 2 verses are from the Nirvana Shatakam and have been purportedly shown to stimulate Gamma Waves in the brain when used as a stand-alone mantra.
+
+ 
As far as we currently know and understand, Gamma Waves are the highest form of brain activity and the best stage to achieve during meditation.
I can tell you that there are levels above this, but there is not yet any scientific studies showing this.
So for now, this is the best level to try and achieve.
 | Mano buddhi ahankara chittani na'aham Chi'dananda rupah shivo'ham shivo'ham |  |

How To Use? ↟↟
Sit quietly and repeat the mantra using your voice.
When you are developed enough in using this mantra, then you can switch to silent mode.
Focus on a spot between your eyes and approx 3cms or 1 inch inside your brain.
When you are proficient at using this mantra, you may easily spend 1 or 2 hours in meditation.
Stress much?
This mantra has been shown to be highly beneficial for people with stress and anxiety.
Your brain may be Trace Mineral deficient (usually associated with excessive "Sugar"
intake and "glyphosate"
) and this is another cause of stress.