Say as …

You can use the say command with OS X's other voices to get different languages. Use the Thomas voice to get French pronunciation or Yannick for German.

In this example, I will use Thomas and French as this is what I know but Yannick should work as well for German text.

Try the following command in Applications > Utilities > Terminal.app:

say -v Thomas  "Bonjour. Je m'appelle Thomas."

If this is acceptable, you can wrap the say command up in an Automator service; which we will do next.

Automator Service

To create the Automator Service:

1. Launch Automator.app
2. Create a new Quick Action (previously Service)
3. Add a Run AppleScript action

4. Copy and paste in the AppleScript below:

   on run {input, parameters}
       do shell script "say -v Thomas " & (quoted form of (input as string))
       return input
   end run
   

5. Save the service as Speak in French

To use the service:

1. Select text in TextEdit or Safari
2. Control + Click to reveal the Context Menu
3. Select Services > Speak in French

Et voilà ! Other languages and voices are available.

This Automator approach allows you to keep your computer default voice set to your preferred language. While allowing selected text to be read in the alternative voice.

Available Voices and Languages

You can list the available voices and their associated languages with the command:

say -v ?

The available voices can change between versions of macOS. On macOS 10.13, the command returns:

Alex                en_US    # Most people recognize me by my voice.
Alice               it_IT    # Salve, mi chiamo Alice e sono una voce italiana.
Alva                sv_SE    # Hej, jag heter Alva. Jag är en svensk röst.
Amelie              fr_CA    # Bonjour, je m’appelle Amelie. Je suis une voix canadienne.
Anna                de_DE    # Hallo, ich heiße Anna und ich bin eine deutsche Stimme.
Carmit              he_IL    # שלום. קוראים לי כרמית, ואני קול בשפה העברית.
Damayanti           id_ID    # Halo, nama saya Damayanti. Saya berbahasa Indonesia.
Daniel              en_GB    # Hello, my name is Daniel. I am a British-English voice.
Diego               es_AR    # Hola, me llamo Diego y soy una voz española.
Ellen               nl_BE    # Hallo, mijn naam is Ellen. Ik ben een Belgische stem.
Fiona               en-scotland # Hello, my name is Fiona. I am a Scottish-English voice.
Fred                en_US    # I sure like being inside this fancy computer
Ioana               ro_RO    # Bună, mă cheamă Ioana . Sunt o voce românească.
Joana               pt_PT    # Olá, chamo-me Joana e dou voz ao português falado em Portugal.
Jorge               es_ES    # Hola, me llamo Jorge y soy una voz española.
Juan                es_MX    # Hola, me llamo Juan y soy una voz mexicana.
Kanya               th_TH    # สวัสดีค่ะ ดิฉันชื่อKanya
Karen               en_AU    # Hello, my name is Karen. I am an Australian-English voice.
Kyoko               ja_JP    # こんにちは、私の名前はKyokoです。日本語の音声をお届けします。
Laura               sk_SK    # Ahoj. Volám sa Laura . Som hlas v slovenskom jazyku.
Lekha               hi_IN    # नमस्कार, मेरा नाम लेखा है. मैं हिन्दी में बोलने वाली आवाज़ हूँ.
Luca                it_IT    # Salve, mi chiamo Luca e sono una voce italiana.
Luciana             pt_BR    # Olá, o meu nome é Luciana e a minha voz corresponde ao português que é falado no Brasil
Maged               ar_SA    # مرحبًا اسمي Maged. أنا عربي من السعودية.
Mariska             hu_HU    # Üdvözlöm! Mariska vagyok. Én vagyok a magyar hang.
Mei-Jia             zh_TW    # 您好，我叫美佳。我說國語。
Melina              el_GR    # Γεια σας, ονομάζομαι Melina. Είμαι μια ελληνική φωνή.
Milena              ru_RU    # Здравствуйте, меня зовут Milena. Я – русский голос системы.
Moira               en_IE    # Hello, my name is Moira. I am an Irish-English voice.
Monica              es_ES    # Hola, me llamo Monica y soy una voz española.
Nora                nb_NO    # Hei, jeg heter Nora. Jeg er en norsk stemme.
Paulina             es_MX    # Hola, me llamo Paulina y soy una voz mexicana.
Samantha            en_US    # Hello, my name is Samantha. I am an American-English voice.
Sara                da_DK    # Hej, jeg hedder Sara. Jeg er en dansk stemme.
Satu                fi_FI    # Hei, minun nimeni on Satu. Olen suomalainen ääni.
Serena              en_GB    # Hello, my name is Serena. I am a British-English voice.
Sin-ji              zh_HK    # 您好，我叫 Sin-ji。我講廣東話。
Tessa               en_ZA    # Hello, my name is Tessa. I am a South African-English voice.
Thomas              fr_FR    # Bonjour, je m’appelle Thomas. Je suis une voix française.
Ting-Ting           zh_CN    # 您好，我叫Ting-Ting。我讲中文普通话。
Tom                 en_US    # Hello, my name is Tom. I am an American-English voice.
Veena               en_IN    # Hello, my name is Veena. I am an Indian-English voice.
Victoria            en_US    # Isn't it nice to have a computer that will talk to you?
Xander              nl_NL    # Hallo, mijn naam is Xander. Ik ben een Nederlandse stem.
Yelda               tr_TR    # Merhaba, benim adım Yelda. Ben Türkçe bir sesim.
Yuna                ko_KR    # 안녕하세요. 제 이름은 Yuna입니다. 저는 한국어 음성입니다.
Yuri                ru_RU    # Здравствуйте, меня зовут Yuri. Я – русский голос системы.
Zosia               pl_PL    # Witaj. Mam na imię Zosia, jestem głosem kobiecym dla języka polskiego.
Zuzana              cs_CZ    # Dobrý den, jmenuji se Zuzana. Jsem český hlas.

Have you tried the service "Add to iTunes as a spoken track"? You can easily assign a keyboard shortcut to it an then manage the tracks with iTunes.

I found this tutorial on youtube.