Csdrhrt

Using more compound sounds is a good start. Part of your problem comes from the syllables you're using - most of them are only 1 or 2 letters. The longest of your sample names is all of 5 letters - there's not a lot of room for variety when all the names are 3 or 4 letters long.

I recommend adding more consonants to most your syllables, especially some of the less common ones (x, z, q, etc.). This way, your names will have different lengths as well as different spellings, which will make it easier to help tell them apart.

A trick I use is to make sure that the first three letters of any character's name don't match the first three letters of any other character's name. You could try something similar, using the last three letters instead.

Your sample names could be changed to be something like this: Elish, Arax, Efa, Ermdril, Ayrgo, Ilthaz, Ilu.

You wish to maintain the brevity of the names, so I would suggest inserting silent consonants at the end of some, changing Ara to Aragh or Arah to differentiate it visually from the other names.

You could consider adding a z in the first syllable. Ara could become Azragh, Arzah or Arzagh.

Minor changes to names can be enough to help make them easier for the reader to recognize as unique to the character. Some of your names do sound similar, but they obey the constraints you imposed. Using consonants that are pronounced as vowels in other languages might help with the variety unless the constraint requires a true vowel to be the initial letter.

If it is the vowel sound that is what matters, in some languages H is not pronounced though it is present, with hotel being pronounced otel.

You might want to consider adding an apostrophe to a name, such as Eril and it could become Er’il.

Changing the appearance of the name can be enough to make the reader see them as very different names.

Direct answer: Some consonants in English sound similar. They tend to fall in groups:

b, d, p, t, th, v

c, ch, g, j, k, q, s, sh, x, z

f, p

h

l

m, n

r

w

y

That is, "Emma" and "Enna" sound a lot alike, but "Emma" and "Ecka" sound very different.

I note that even within your "start with a vowel and 2 syllables" rule, you seem to be choosing names that are simpler than that rule requires. Why not "Alish" or "Unkminth", for example? How about "Oomnitz" or "Eiroof"? Etc.

In any case, I wonder if you are not making a mistake common to many writers -- not to mention people in other professions. You made up a rule, now you find that the rule is causing you all sorts of trouble, and so you double down and try to figure out how to live within the rule rather than considering going back and changing the rule to something that WON'T cause you trouble. Why do names have to follow this pattern? Is it necessary for the story to work that all names must follow a pattern? Or if there is some reason why they have to follow a pattern, does it have to be THIS pattern?

I'm a software developer in real life. I've had many times that a company I worked for made some rule that all our software must be written in such-and-such a way. Sometimes these rules turn out to cause problems. And I go to the boss and say, "Rule X is causing us all kinds of problems, it's making every project take much longer to complete [or whatever problem]. I suggest we do Y instead." And often, the boss's response is, "No, the rule is X." "Yes", I say, "I know that's the rule. But that rule is causing us trouble." And he'll reply, "No, you don't understand. The rule really is X. See, it's right here in this memo." And we go around and around until I give up.

As others have suggested increasing the length of the name in letters and adding markings (accent marks, apostrophes, et al.) may help make the names more distinctive. In some cases this can be accomplished with little or no change in pronounciation.

For example:

• Elish: Elissh, Eelisch


• Ara: Arah, Aruh, Ára, Eirah


• Efa: Eefah, Efaa, Eefa'


• Eril: Er'l, Erill, Eeril


• Aygo: Aygho, Eigoh


• Ina: Ína, Inuh


• Ilu: Ilou, Ilooh

Alternate spelling may not be possible if you are trying to maintain a certain cultural feel (e.g., Semitic language).

It also seems that all of your example names start with a long vowel. This reduces variety (beyond not using o, u, y, or dual-vowels as starting vowels) and increases the difficulty of using dual consonnants after the first vowel (because in English such usually makes the preceding vowel sound short). This also places emphasis on the first syllable, reducing the perceived variety of the names. (Your example names may also be a little artificially different in the vowel sounds between syllables, only one uses a long vowel and then the short version of that vowel and none has internal assonance. You may also being trying too hard to make the names sound feminine to an English-speaking ear; some of the sound features seem to hint at that.)

Most of the example names also have no terminating consonnant, and the two out of seven that do have softer terminating consonnants. This further limits length (and diversity of length and sound).

Some examples of using sound features missing or rare in your examples: Adgail, Obaat, Ilgad, Onpheth, Unev, Elchad, Onur, Esbath, Orgrod, Innith, Eddel, Oshon, Ergrat, Aytphail, Opthol, Errel, Ebnech, Umthaph, Oodmach. (These generally sound less feminine to an English-speaking ear, but mostly have a Semitic feel and seem to be significantly distinct from your examples and from each other.)

Besides making the spellings (and pronounciations) more distinct, it may also be helpful to use sounds, spellings, and markings that help the reader map the name to the character. An acute accent may give a sense of specialness possibly fitting one who acts like a princess (stuck up nose or tender heart); a longer name (in spelling and/or pronounciation) may associate with importance (self-importance, narrative importance, importance to parent), a shorter name may associate with social reserve or abruptness in speech (an apostrophe/elision may increase this effect); harsh consonnant sounds might associate with a grumpy or homely person, bright vowel sounds might associate with a more lively person. Name sounds can associate with physical appearance, personality, social position, occupation, etc. (and this association can be lightly emphasized by the author). This can also be done by contrast, e.g., a pretty name associated with a woman with an ugly personality.

For one character's name, word play with a somewhat common or important foreign untranslated word could help solidify the association. For example:

He blessed his mother as he entered the tent. "The well is opened now."

"You must be hungry. Have some aygoht!" She handed him a steaming bowl and urged him to sit and eat.

The spicy lentil stew from his dear mother, as pleasant as it was, did not warm his heart as much as remembering his brief talk with the priest's daughter. Rich, warm, wholesome — well, named indeed, Aygo, daughter of Eliob.

(If the culture makes heavy use of word play or some characters have significant literary aspects, as might be common among priestly families, such might be used a little more extensively as a reminder or mnemonic. Besides affectionate associations, teasing and name calling can exploit word play.)

One can also use in-story name confusion to help remind the reader of the name associations. This has very limited application, but may be helpful if applied to similar names that may be more likely confused because of similarity of character, scene, role, or other aspect. Even a single in-story name confusion may not only help the reader remember the name associations but also feel less incompetent when confused.

Family and town associations can also help the reader associate names with persons. For example, if Elish is the well-loved daughter (or sister) of the prominent priest Elishem, the closeness of the names may help the reader connect those two names (and Elishem may be more easily associated), remember the emotional closeness, and remember who Elish was. Accidental assonance, consonance, etc. can link the name to some aspect easily linked with the character similarly to how the feeling of a spelling or sound can be linked with aspects of the character. For example, Elbeth of Bethlehem may be more memorable than Dorach of Bethlehem.

Another technique which may help readers is to occasionally insert characteristic traits when introducing a character into a scene. For example, "Elish thundered into the room" could help the reader remember that Elish is the bold, temperament, heavy-set woman rather than her petite, reserved sister Elib. When other characters talk about a character, relationship aspects will naturally be presented. For example, a high status woman is likely to be spoken of more formally, using additional distinctions like family association. This can be done with a mocking tone for someone whom the speaker feels takes their status too highly: "Elish of the house of Eliezer! She may be the High Priest's wife but that doesn't mean she knows everything!" Such is similar to how diction and other manners of speech can distinguish characters in dialogue.

Introductions and telling another character about an interaction can provide opportunities for natural repetition of identifying information For example: [returning from the market] "I found a nice cluster of dates. Elib's stall had the most beautiful shawl. I wish we could afford it, but it is probably sold by now. Oh, and Elba said the barley harvest is likely to be rich this year." Such establishes Elib as a seller (likely maker) of fine clothing as distinct from the similarly named Elba who has some agricultural connection. (This seems related to the cabbagehead technique; instead of explaining somewhat common knowledge in the setting one is helping the reader associate a name with a character.)

You're unconsciously limiting yourself within your rules

I decided to go to a baby name website and find some real names that fit your restrictions.

Anna

Amber

Amy

Audrey

Alice

Adele

Angel

Ali

April

Alma

That's just the first first page of A's. And I was skipping anything with that was too similar to anything I had already picked. There are plenty of names for you to use. You just need to find/create them.

English has only five vowel letters, but there are more than five vowel sounds

There's at least 3 different starting vowel sounds in the list that I made (Anna, Amy, and Audrey) even though they all start with the same letter. Pay attention to the sounds you are using, and make sure that you are taking advantage of all of them.

Pay attention the beginning and the ends of words

People pay more attention to the beginnings and the ends of things, while skipping over the middle. You may have seen some trivia pieces that take advantage of that fact:

I cnduo't bvleiee taht I culod aulaclty uesdtannrd waht I was rdnaieg. Unisg the icndeblire pweor of the hmuan mnid, aocdcrnig to rseecrah at Cmabrigde Uinervtisy, it dseno't mttaer in waht oderr the lterets in a wrod are, the olny irpoamtnt tihng is taht the frsit and lsat ltteer be in the rhgit pclae. The rset can be a taotl mses and you can sitll raed it whoutit a pboerlm. Tihs is bucseae the huamn mnid deos not raed ervey ltteer by istlef, but the wrod as a wlohe. Aaznmig, huh? Yaeh and I awlyas tghhuot slelinpg was ipmorantt!

The more you differentiate the the ends, the more distinct the names will be. And if two names have very similar ends, then it becomes extremely vital that the centers use consonants that feel very different in the mouth (compare Anna to Alma for example)

Your rules have a lot of design space - it's up to you to decide how much of it makes for good names

Here's some more names following your rules:

Unter

Omething

Ustice

Andwich

If you can't tell, I just took normal everyday two-syllable words, and lopped the first consonants off. These look a bit odd to be names, but they should be an indication that there's a lot of space in your rule for creative and unique names once you go digging for them.

You've dug yourself a hole there with the two-syllables-starting-with-vowel rule.

The main trick used in many places for distinguishable character names is to have them start with different sounds. And you've just cut that selection down to about 20% of the vocabulary...

Names, in real life as in stories, are there to distinguish people (and things) from each other. As such they are rarely too similar to each other. Any system or rule that enforces too close similarity would be abandoned as useless. Whenever such a system was artificially upheld (e.g. royal names in the same lineage, where traditionally people were often named after fathers, grandfathers, etc.) you had added discriminators. John I, "the cruel" and John II, "the great" and John III, "the conqueror".

Your characters might have actual names, which are confusingly similar, and also nicknames which are more often used.

Another problem with this system is how the brain reading English doesn't require spelling to be correct, especially if the word has 4 or more letters. Basically, it's entirely possible to read the intended misspelling word so long as the first and last letters are in the correct place and the letters in between are disordered. You can search online for examples that demonstrate this effect, and it's not something that is ruled based so much as how your brain processes information... Because you have lots of names that start with one of 5-6 letters and have a handful of letters between the end. This is even more troublesome as the names end on vowel sounds too. I would avoid repatition of middle letters and ending with vowels to help this move along.

I'd also like your thoughts on this, but as mentioned, you don't have many Y vowel names, though Y is rarely a Vowel in English if it starts the word, to the best of my knowledge. Y isn't the only "Sometimes" vowel in English language. For example, the Letter W is sometimes a vowel as well, though only when preceding another Vowel such as in Now, Cow, How, Vowel (hehe) and the second instance in Wow. It's also a vowel in loan words from Welsh, so you might be able to find some Welsh names where this occurse (it's important that you look up what a Welsh "W" sounds like on a IPA chart and then make sure the names duplicate that sound in the leading W. I'm not sure it counts in these instances in the Welsh Language. But, a few Welsh names will definitely stand out.).

Finally, made up names or very obscure names (all of your examples are either one of the two and I can't tell which) will need some extra security to ensure it's different, though similar leading letters can show a trend (For example, all names either start with an A rather than a Vowel, or they all start with a similar sound.). For example, in Star Trek, a general rule was that all Vulcan Males names started with an S and ended with a K and contained five letters total (Spock, Sarek, Sybok) and all Vulcan Female names Started with a T' followed by a short 3-4 letter set (usually a T'P T'Pringa, T'Pau, though). Though both genders had names that loosley followed the opposite gender rules (female Saavik from Films and male Tuvok from Voyager). While very limited, there are some real life languages with a short list of names (Latin/Roman names and Japanese Names tend to have rather short lists as well). Other systems have a broad range of names, but the traditional rules tend to limit the names. For example, Irish naming conventions traditionally hold that the first born child of a gender will be named such that [Father's Father/Mother's First Name] [Mother's Father/Mother's First Name] [Surname]. The second child of that gender would be a reversed order using the mother's parent for the first name and father's parent for second name. Presumably this would use middle names for children 3 and 4. This isn't always followed if the grandfathers are both Sean or if the name sounds terrible, but it did help to narrow a very broad list of traditional names.

Your rules might be too limiting, given how few vowels English has, even after you remember y is a semivowel. Obviously "use consonants instead" would require a huge rewrite, even if you can tweak the "reasons" for the rule to make it work. But I can think of three less radical ways to expand the options available to you. What they all have in common is that the people living in your culture might have found them useful, because the limits you're encountering would be an even bigger problem for them than they are for you!

One is to use accents (forgive me for using that term loosely for diacritics too). A name, especially that of a major character, could be distinctive because of accents, and not necessarily on the vowels. My favourite example on consonants is the ny sound ñ.

The second is to revisit what a vowel is. Vowels use an open vocal tract, while consonants partially close it; and when letters move from one language to another, or inspire new letters, what's a vowel vs what's a consonant can change. For example, the Roman A is a vowel, like the Greek alpha that inspired it, but that was on turn inspired by the Phoenician aleph. Aleph appears on several languages, and while the details vary among them it's typically either a consonant or a conbined consonant-vowel sound! So what's a vowel in your story, and why?

My third suggestion is to look beyond "the 26" letters in English. What about this, or this? English has also lost letters over time (albeit often consonants, but that's still a useful part of your names' variety because they still contain accents). Most amusingly, the ampersand was once treated as the twenty-seventh member of the alphabet!

Most of your example names only use monophthongs. You can expand the different vowel sounds available if diphthongs are also allowed.

• ai, ou, au, ei, ie, etc.

Other sounds are not diphthongs but are still different:

• ee, oo (book), oo (zoo)

And in English a single vowel followed by a consonant-vowel pair (the vowel is often E) will usually make a diphthong too:

• aXe, iXe, oWe, uXe

Note that depending on the exact combination this might or might not work:

• 
  Alice /æləs/ - A (monoph.), i (reduced)


• 
  Eileen /eɪliːn/, /aɪliːn/ - Ei (diph.), ee (long)


• 
  Isabella /ɪsəbɛlə/ - I (monoph.), a (reduced), e (monoph.), a (reduced)


• 
  Odelia /oʊdiːliː(j)ə/ - O (diph.), e (long), i (long), a (reduced)


• 
  Uma /uːmə/ - U (long), a (reduced)

According to quora:

The letters of the alphabet that are used least frequently in the
English language are Q, J, Z and X. Each of these letters is used in
less than one percent of English vocabulary. Of these, X is the least
common letter at the beginning of words.

Throwing one of those in can help differentiate a main character. Don't do it with all of them of course, but you can still use your rules and spice things up.

You can also explore actual NAMEs that follow your rules and then, change them.

So there's the name Erin. Take that and replace the N at the end. Erig, Eril, Erif, Erig, Erit, and so forth. You've already done that, but you want to make sure that you don't overuse the Eri beginning. Use that one time. Same with endings. You have two names starting with vowel, then consonant then I. Another pattern I see is not many names that have odd letters or go "below the line" visually. So letters such as y, j, q, p can spice things up if you can get them.

And let's take the some of the baby names in the A's helpfully looked up by Arcanist Lupus and use them as leaping off points:

Anna
Variation: Una, Atha, Ena, Enna, Onna, Ona, Ina, Acha, Entha, Antha, Azza, Axa, Aga, Appa,

Amber
Variation: Umber, Omber, Imber, Umzer, Umquer,

Amy
Variation: Ume, Umi, and so on...

Audrey
Variation (keep playing, until you get something that doesn't even seem like it has Audrey as the starting point): Aubry, Oudry, Eudrey, Eudray, Eubray, Ooquay,Epray

Alice
Variation: Elis, Alich

Adele
Variation: Afel, Agelle, Ahele, Ajele, Akel, Alele, Amele, Anele, Asele, Atele,

And there's also just plain words to start with:

again (Agin, Agene, Ogin, Ogain, Igain), able (Abell, Ubelle, Obele), apple (Appel, Oppel), away, (Awey, Awhey, Owey, Uway), acid (Achid, Acal, Ocid, Ucide, Ecid), action (Akt, Oction, Ection, Uction)

So now we have K's and W's coming in-- the important thing is to expand your sound library so you don't retread.

Things that can visually help with differences: double letters (nn, pp, ll), unusual beginnings and uncommon letters.

Avoid lots of beginning rhymes. Don't have a lot of Er, Ar, Or, Ir beginnings. Since all of your names start with vowels, that second letter can be crucial. Avoid similar endings as well. If you end one name with an --ay, don't do it again unless you can find a way to differentiate. I also noticed that there's not a lot of O and U action happening at the start of any of the names. Lots of E's and A's and I's, which can often lead to the same sounds happening.

And maybe just have one of your characters have a name that is an actual word such as aqua. That would be notable to your real-world reader. Basically, each name can have something a bit quirky to it that makes for visual or auditory short hand, but they should all have different quirks if you can manage it.

Those things can be Double Letters, Odd letters, real life word, different length than the rest (do vary this---you don't as much as you should!)

As Tom says, applying the rule that these women's names must start with vowels cuts the selection to about 20%. So perhaps you could allow some consonants at the starts of their names. Perhaps those that have liquid sounds, e.g. L, R, W and Y.

When I imagine characters in a story, I try to keep track of the initial of the name of each, to keep it clear in my mind which name is which character. This works best if characters who appear together have different initials. So allowing more options for women's initials helps.

Use consonants at the ends of the names.