Biblingo offers multiple pronunciation systems for both Greek and Hebrew. For Greek, we offer Modern, Koine (also called Reconstructed Koine), Early High Koine, and Erasmian. For Hebrew, we offer Modern and Biblical (also called Masoretic). Users can choose their preferred pronunciation system in their profile settings, and that system will be used for the audio across the platform.
The pronunciation type is mostly a personal preference. Some people have very strong opinions about pronunciations, but we tend to be pretty neutral. There are generally two questions to consider:
Is the system is pedagogically advantageous? This could be based on how many sound distinctions there are between letters (the more the better), or how many resources are available with this system.
Does the system accurately represent any historical period of the language's pronunciation? This question can be important if you want a more "authentic" experience of the language, which can be useful for motivation.
Below is typically how we break down each system.
For Greek:
Modern - if you ever plan to learn the Modern Greek language, you should probably go with Modern pronunciation. Otherwise, it can be difficult pedagogically because all the vowels sound the same. However, there is a certain beauty to this pronunciation, and it also opens the door to more (and higher quality) audio recorded by native Greek speakers. It is also the only system that we know for certain is "authentic", as it accurately represents how modern Greek speakers pronounce the language.
Koine (reconstructed) - this is perhaps the more common system among those who do "conversational" or "spoken" biblical Greek, so it can be pretty useful if you plan to be in circles that use this approach. It makes more sound distinctions than Modern, but still not as many as other systems. In terms of historical authenticity, this system is meant to be an authentic historical reconstruction, but it's accuracy is debated.
Early High Koine - also more common among those doing conversational/spoken biblical Greek, but probably not as common as Koine (reconstructed). However, there are 2 big benefits here: (1) it's the most similar to Erasmian, so it will overlap with the seminary world well, and (2) it makes the most pronunciation distinctions between letters, which is helpful pedagogically. This system is also meant to be an authentic historical reconstruction, but it's accuracy is also debated.
Erasmian - this is the most common system used in seminaries, so it could be useful if you plan to be in the world. However, since typically speaking/conversation is not emphasized in that world, it doesn't matter that much. Otherwise, this system is sort of a weird "in between" because it does not represent an actual historical pronunciation, nor is it the most pedagogically advantageous. However, it terms of sound distinctions, it is more advantageous than both Modern and Koine.
For Hebrew:
Modern - the logic is similar to Modern Greek above. If you ever plan to learn the Modern Hebrew language, you should probably go with Modern pronunciation. Otherwise, it can be difficult pedagogically because there are less sound distictions. However, it does open the door to more (and higher quality) audio recorded by native Modern speakers. It is also an authentic system used by Modern Hebrew speakers.
Biblical (Masoretic): similar to Early High Koine for Greek, it it makes more pronunciation distinctions between letters, which is helpful pedagogically. It is an authentic historical reconstruction that represents one of the reading traditions around 1,000 AD, which we know reflects earlier times. However, we are not sure how accurately it represents the pronunciation of biblical periods.