7. The editor path

There is a third calling convention into Na_VoiceSe that skips the phonology engine entirely, and it explains what a third of the voice samples are for.

Mode 1

The text editor overlay — used for letters, town and player names, patterns, and anywhere else the player types — speaks each keystroke from src/game/m_editor_ovl.c:712:

if (command == mED_COMMAND_OUTPUT_CODE) {
    int voice = mMsg_sound_voice_get_for_editor(editor_ovl->now_code);

    if (voice == 0x85 || voice == 0x80 || voice == 0x81 ||
        voice == 0x82 || voice == 0x83 || voice == -1)
        voice = 0x86;

    sAdo_VoiceSe(voice, 0xFF, 0xFF, 0, 32, 1);      // ← mode 1
}
else if (command == mED_COMMAND_EXCHANGE_CODE) {    // cursor moved onto a character
    if (exchange_code != -1 && mED_exchange_se_list[exchange_code])
        sAdo_VoiceSe(mMsg_sound_voice_get_for_editor(exchange_code), 0xFF, 0xFF, 0, 32, 1);
    else
        sAdo_SysTrgStart(0x36);
}

After both filters, only three things survive: letters (0x5D–0x76), digits (0x53–0x5C), and the click (0x86).

What mode 1 does inside Na_VoiceSe

Na_VoiceSe's two switch (f) blocks handle only cases 0 and 2. With f == 1 both fall through, so:

no digraph merge, no vowel-length table, no silent e;
sou_num_org etc. are never written, so sou_last_num = sou_num_org further down just rewrites stale values — the message-path history is not corrupted, but it is not updated either;
r28 is left uninitialised and never read;
nothing is queued for Sou_SpecialRoutine10;
a arrives at the playback stage as the raw voice code.

The editor always runs at spec 5 or 6 (see gating), which routes 0x86 to NA_SE_BEBE and passes everything else through. The final guard is if (a != 0 && a <= 0x77), and letters and digits both satisfy it. So:

typing 'a'  →  Sou_VoiceStart(subtrack, 0x5D)  →  instrument 0x5C
typing 'z'  →  Sou_VoiceStart(subtrack, 0x76)  →  instrument 0x75
typing '0'  →  Sou_VoiceStart(subtrack, 0x53)  →  instrument 0x52

What this tells us about the sample set

Trace the reachable phoneme codes across the whole engine:

Code range	Instruments	Reached by
`0x01`–`0x52`	0–81	the phonology engine — short/long vowels, consonants, all 52 two-character digraphs plus `you`
`0x01`–`0x40`		also the anti-repetition random substitution (`rand() >> 2`)
`0x53`–`0x76`	82–117	only mode 1 — one entry per digit and letter, in order (on bank 157, instrument 82 is instead the `you` substitute, see below)
`0x77`	118	the `you` digraph, and nothing else

The 0x53–0x76 block is exactly 36 codes: ten digits then twenty-six letters, in the same order as the voice-code alphabet, and it is unreachable through any dialogue. The obvious reading is that these 36 samples are the spoken names of the digits and letters — what you hear when typing a name one character at a time.

Confidence. The code path is unambiguous; the interpretation of the samples as letter names is inference. It is testable: extract instruments 82–117 from bank 156 and listen. It also predicts that bank 157, which stops at 83 instruments, is a phonology-only bank — and that is exactly what it is.

Why bank 157 is short

Spec 3 (Wendell, Pete, Booker, Jack) uses sequence 244 / bank 157, which has 83 instruments — one more than the phonology output range (0x01–0x52 → instruments 0–81) — and omits the letter-name block that spec 3 can never reach, since the editor is always spec 5 or 6.

The 83rd instrument is not spare. Sequence 244's dynamic table maps codes 0x53–0x76 to explicit silence and maps you (0x77) to instrument 82 — a sample reachable through no other path, played at a lower note than the other two voices' you (semitone 41 vs 44; see the disc page). So bank 157 carries a dedicated you substitute, and spec-3 voices lack nothing audible. Whether instrument 82 is an actual "you" recording is testable the same way as the letter names: extract it and listen.

This corrects two earlier readings. Working notes once described bank 157 as "collapsing every digraph sample above 0x53 onto one sound" — nothing above 0x53 is a digraph, the block is not phonology at all. A later revision of these pages then claimed the dynamic table "clamps out-of-range entries to the last routine" — it does not; the mapping of 0x77 → instrument 82 is an explicit table entry, verified on disc.