Is there any way the Guru makes sure a student can properly pronounce the Vedas, has committed it to memory, and understands the concepts?
Today, you will get a diploma from an accredited university, which means that you are qualified in the subject and recognized by the professors.
Is there any similar concept in the traditional Vedic schooling?
Also, what does the Guru do about a student who has a speech impairment, is dyslexic, or is unable to grasp Vedic concepts or cannot memorize easily?
In the gurukulam i.e Vedic pAthashAla in this case, there is a sequential method of learning vedas. The focus is mainly on chanting/reciting them as per the proper siksha (part of vedAnga).
Periodical exams are conducted at the paathashaala in order to ascertain the progress of students. After checking the fluency in chanting they are promoted to the next level of chanting and so on.
The various pathas or recitation styles are designed to allow the complete and perfect memorization of the text and its pronunciation, including the Vedic pitch accent. Eleven such ways of reciting the Vedas were designed - Samhita, Pada, Krama, Jata, Maalaa, Sikha, Rekha, Dhwaja, Danda, Rathaa, Ghana, of which Ghana is usually considered the most difficult.
The students are first taught to memorize the Vedas using simpler methods like continuous recitation (samhita patha), word by word recitation (pada patha) in which compounds (sandhi) are dissolved and krama patha (words are arranged in the pattern of ab bc cd ...); before teaching them the eight complex recitation styles.
A pathin is a scholar who has mastered the pathas. Thus, a ghanapaathin has learnt the chanting of the scripture up to the advanced stage of ghana. The Ghanapatha mode of chanting is so called because the words are repeated back and forth in a bell shape. The sonority natural to Vedic chanting is enhanced in Ghana. In Jatapatha, the words are braided together, so to speak, and recited back and forth.
The samhita, pada and krama pathas can be described as the natural recitation styles or prakrutipathas. The remaining 8 modes of chanting are classified as complex recitation styles or Vikrutipathas as they involve reversing of the word order. The backward chanting of words does not alter the meanings in the Vedic (Sanskrit) language.
Apart from this they also have other lessons like purAnas and vedAngas including vyakarana (grammar). So those not able to chant vedas could learn other shastras where chanting is not necessary.
Even today the vedic gurukulas have exams and they have topper (gold medalist) etc. I know a person in Bombay who was topper in his class while learning samhita. After completing the studies they are awarded the respective certificates.
First a distinction between a Guru and Acharya has to be made as per Sanskrit and Shastras.
Guru is an enlightened being, if a Guru accepts a disciple then the purpose of disciple is well understood.
If the Guru takes the responsibility to make a person learn and enunciate Vedas properly then he/she just makes it happen even if it involves overcoming obvious and not so obvious physical and mental limitations provided parents cooperate. This happens even today in a few Gurukuls run by Gurus (Guru as defined in Sankrit, not english)
Unfortunately, most of the branches of Vedas are lost for ever only a few remain.
Apart from that in acharya based Gurukuls and patshalas they have their own certifications, some are more prestigious than other.
For example, Tenali exam is considered most prestigious for Sanskrit certification.
References:
